After starting my PC today, I was staring at a little message on my screen that said “Missing operating system”. At first I was a little bit shocked, but of course I knew that this *most often* only means that either my disk has some small disk errors or my master boot record is damaged. 
Run chkdsk to repair disk errors
1. Step Find your Windows DVD that you used to install Windows 7,8 or 8.1
2. Step Start your PC, insert your Windows DVD and hit a key when you are asked to (to boot from DVD). It is possible that you have to change the boot order in your BIOS to boot from DVD.
3. Step Follow the instructions on the screen, but don’t install Windows 7, instead click on “Repair your computer“:
The installer will now search for Windows installations on your PC and list them all. Select your Windows 7 installation and click on next.
4. Step Open the command prompt.
Attention: Do NOT click on “System Restore” or “System Image Recovery”. If you try to restore/recover your system that way, you might damage your Windows 7 installation irreversibly.
5.You will probably be in a folder X:\sources\ . Don’t worry, if your partitions are still there you can run a chkdsk on them.
Run a chkdsk for your main partition (e.g. C:), to do that enter:
chkdsk c: /f/r
/f /r will both fix errors and recover lost data.
/f will only fix errors on your disk
/r will only recover lost data
This will, in most cases, repair your disk errors and you will be able to start Windows 7 again.
Windows Bootrec.exe Commands – Repair MBR
While you’re at it, you also might want to repair and fix your MBR (Master Boot Record), add a new boot sector and scan your disk for Windows 7 or Windows 8 installations.
/fixmbr
This will create a new Master Boot Record, but will not overwrite your existing partition table.
/fixboot
This will add a new boot sector. If you boot sector is damaged you might not be able to start your system.
/rebuildbcd
Scans your disk for Windows compatible installations, needed to repair your Windows 7 or 8 installation. If you can’t find any bootable Windows installations, also try using the command bootrec /ScanOs
I’m Stuck In X:\sources\, Help!
No worries, that’s alright. X is a system-reserved partition that aids you with the recovery, so if you see the X:\sources and not C:\ don’t worry and follow the instructions above.
Please always make sure to remove additional hard drives or USB sticks are currently plugged into your PC, you may be booting from a corrupt (external) drive and wouldn’t even know it or you may be booting from a stick that isn’t even bootable and then you’d also receive the error “missing operating system”
Hey..really a good post.You explained clearley.But one thing i didn’t understood..why don’t you have a Social Bookmarking..so that we can tweet this post on Twitter..
I seen the missing operating system message about a month ago. The strange part is it didn’t work for about a day. I didn’t feel like messing with it, because I just had spent hours tweaking it to my liking. Anyway the next day when I decided to fix it, I turned on my computer and it booted up normal without me doing anything. Which is strange because I tried booting it about a dozen times and got the error message each time. I still haven’t figured out why it messed up and started working on its on.
So maybe another possible fix is to give it a day!
@Kishore actually, I removed it to speed up the website speed, but I’ll ad it again. We’re moving to a new server soon anyway.
@Andy: Just a theory, but maybe you had some bootable hard disks connected. Sometimes it’s trying to boot from them and then Windows will display the message: Missing operating system
Another theory is that you had some disk reading errors when you tried to boot it the first time, this can happen.
If I were you, I would still do a chkdsk to check the hard drive for disk errors!
sOliver, I only have one hard drive in that computer. I actually did run the chkdsk and bootmgr, nothing showed errors. Tried all available options, so I was going to wait and reinstall the os the next day. Then it worked! I’ve never had any hd problems on that computer, I did go from vista to ubuntu to windows 7. But windows 7 worked for about 3 or 4 days before the error!
That is a very good post but the thing is: I DONT HAVE THE DVD!!!! :(
and i dont know what to do…:(
Please help me!!!
Hi – I appreciate any help. At the System Recovery Options screen when I click Load Drivers, I do not know what files and where they are on the DVD so I cannot tell it what drivers to load. Thanks again for any help.
@Sally you will need the DVD to repair Windows 7.
@Harry it could be asking for SATA drivers or it wont recognize your hard drive. You have to load those drivers from a floppy disk or CD.
So, go to the site of your chipset manufacturer, download the SATA drivers and then copy them to a disk or CD. Then load those drivers when you’re asked to.
I completed the whole process including /fixmbr; /fixboot & /rebuildbcd. They all completed successfully. When I tried to reboot, I got the message “BOOTMGR is missing” – Any suggestions?
Harry, can you try to run this: chkdsk /f /r
Just to make sure that you don’t have a corrupt hard drive sector.
Actually /fixmbr should fix your master boot record, so I’m pretty clueless why you are still receiving the error BOOTMGR is missing.
If your hard drive is corrupt it might be an explanation why you are still getting the error.
Anyway, if nothing helps, you could give this a try, although to me it sounds like your hard drive is corrupt:
http://windows7themes.net/how-to-repair-windows-7-sytem-files.html
Hi Oliver:
Thanks for your help and responses. I had to call Microsoft and use 1 of my 2 free support incidents. They helped me do a custom re-install of Windows while saving my documents and settings although I did have to re-install all programs. They said that the repairs chkdsk had made had overwritten some of the sectors where the system files are stored thereby corrupting the BOOTMGR (a case of win some lose some). The win is that I am back up and running. The loss is that chkdsk repairs can damage system files causing you to have to re-install Windows and all programs.
I did this before seeing your response. Microsoft did NOT have me try to run sfc.exe /scannow which seems like a more direct approach saving the time and trouble of re-installing Windows AND programs. Sorry I can’t let you know if sfc.exe /scannow would have worked.
If someone does need to do this, I suggest trying your suggestion first and if that doesn’t work seeing if you have a step by step protocol for a custom re-install of Windows and restoring email, settings, and files once programs are re-installed – YOU DO HAVE A LOT OF GREAT ANSWERS :). Sorry I did not document all the steps but some of it was complicated related to restoring email, settings and files, especially because some of them were hidden. Last option – contact Microsoft and have them walk you through the process. They were helpful and patient with me.
Thanks again!!
Thanks for reporting, I’m sure it will help some people with the same problems! I’m always running sfc.exe first when I run into any problems, it will often fix a lot of problems.
Glad that you’re up and running again :D
Under system recovery options
I do not have any options to choose from
What should i do?
Does the installer find Windows on your system? If it does, did you try to start in safe mode and command prompt via F8?
If you didn’t, try that first and then run the commands above, especially chkdsk and sfc.exe
Hi, great post that gave me something to work with.
However my boot win 7 dvd cant help me find any installation to recover, its empty and when I try to run CHKDSK it says that the unit is in RAW format and that CHKDSK cant be run on thoose units.
If I try sfc it just says that a system repair is waiting for a restart in order to be able to complete, restart win and run sfc again….
Feels like im kinda stuck so if anyone have any good ideas im eager to try anything right now!
Thanks
Kris
Are you getting this error?
The type of the filesystem is RAW.
CHKDSK is not available for RAW drives.
If so, there’s a special tool to recover your data, get it here and learn how to use it:
http://www.z-a-recovery.com/unformat-tutorial.htm
Also, if there are no important files on your hard drive, I would simply format the hard drive and re-install.
If ZAR should not work for you, you should download a Linux distribution you can boot from like Knoppix (it’s easy). Then boot from it and backup your data. There are some other free data recovery applications, but I’ll have too look into that and will post them later today.
Hi, recently i’ve tried installing snow leopard into a partition of windows 7 ( i know, stupid). Since then i’ve come to the “missing operating system screen” I downloaded a free windows 7 repair disk, and it can’t locate my hard disk. I’m guessing i need the drivers, but i don’t know which ones i need, and where to get them
. I have a toshiba satellite a205-s5814 windows 7 ultimate 32 bit. I’ve also tried the bootrec options, everything except (/fixboot) work. /fixboot says my volume is unrecognized or corrupted. I can still access my hard disk in the load drivers option, and can see all my original files so thats good? A clean reinstall is my last option i guess. Any help would be greatly appreciated.
How long should it take for chkdsk /f /r to run? Minutes, hours, days?
Mine shows stage 4 of 5 (verifying file data) and is only showing 10% complete.
@Bryan I hope your tried running chkdsk as suggested above.
@jl chkdsk can take 2 hours or longer but it really depends on a lot of factors, like disk size, corrupted sectors that have to repaired, etc.
Most of the the time when you encounter the message “Missing operating system” all of your files will still be there. There are worse error messages.
The Windows 7 OS isn’t listed under System Recovery Options. Message from rebuildbcd:
Total indentified Windows installations: 0
Does this mean a reinstall?
My computer is saying Missing Operating System.
I tried to install the Windows 7 DVD but the drives that it asks me to select are needing to formatted but it shows an error message when I try to format them ( c drive, d drive).
In command promt after chkdsk c: f/r/ I have that message saying
The type of the filesystem is RAW.
CHKDSK is not available for RAW drives.
How do you suppose I go about downloading ZAR if I cannot get on my computer?
Thanks for your support
You are trying to actually format your hard drive, but you can’t? This could mean that your hard drive has some severe errors if Windows can’t even format it. What does the error message say? At least Windows recognizes the hard drive, that’s a good start.
What I would is to add the “broken” hard drive to another computer. On that computer you can then download ZAR and run it on the other hard drive if Windows recognizes it (it should).
sorry it wasnt an error message but a message that said Windows cannot format your drive, make sure disk and drive are connected and not a read only file.. I went into properties after right clicking my c drive and it shows 0 free space o used space..? I dont care if I lose any files, I just got the computer about a week ago and it worked fine for a few days, I just want to be able to use it, any ideas would be greatly appreciated.
Also I clicked on startup repair with the 64 bit windows 7 dvd, and it said Partition is corrupt on disk /device/harddisk0
Repair action : Partition table repair
Result faild Error code = 0x140
But then I put the 32 bit dvd in and did the same thing and it said
Partition table does not have a valid system partition
Repair action : Partition table repair
Result : Completed successfully Error code = 0x0
I am wondering if I should try to re-install windows 7, but I have a feeling the drives are corrupted
What do you suggest?
If it was only a corrupt partition, you could still use your hard drive. I’d reinstall Windows 7 and then make sure to format your entire drive. Windows should get rid all the bad sectors (damaged sectors) then and you should be able to use the HDD again.
If it’s an old hard drive you could buy a new one or you will end up with more missing operating systems errors :/
Thanks for the information. I tried to re-install Windows 7 Home Premium Upgrade, but I guess I’d have to install my previous operating system (XP) first, because my product key wasn’t working. :/
Hello,
Most of my computers are running Windows 7 Home Premium or -Ultimate 64 bits. My oldest computer is a HP Pavilion t3060.nl with a single core Pentium 4 cpu, 2,93 gHz. On this computer is Windows Vista Home Premium 32 bits running. However, by restarting that pc the screen turns to black, with only one message (translated in English): failure in MBR, push a button. After pushing a button on my keyboard the system still starts up in Vista. Your advise, described on your webpage, does it also work with the original Vista dvd?
So you are not getting a missing operating system but a MBR failure? And you are on Vista? If so, then you could use your Vista DVD and do this to fix the MBR, should work very similar, but probably not 100% the same.
Thanks for the helpful guide. It got me started but I ran into a problem that a couple people have before me. When I am prompted to select the Windows 7 installation, none appear. When I run CHKDSK, it says:
The type of the filesystem is RAW.
CHKDSK is not available for RAW drives.
I do not recall ever making my drive RAW. It seems to have spontaneously become RAW after restart. I am currently stuck. I do not want to lose any of my data and my hard drives are relatively new (bought the computer in January). I have a copy of Ubuntu on hand that I can load from, but in order to access the Internet in order to download ZAR (if that would help my computer recognize my windows partition) I need to install ubuntu for I only have one disk drive and need to install the drivers for my wireless adapter. I really don’t want to have to deal with creating another partition for ubuntu. Is there a way for me to format my hard drives (it’s a RAID 0 if that matters), reinstall Windows 7, and then recover with ZAR? Also, will this require me to reinstall all of my programs again? Is there any easy way out? I am sorry if I omitting anything or adding unnecessary information. Any help from anyone is greatly appreciated.
Robert you can POSSIBLY get a “filesystem is RAW” or “missing operating system” error message whenever a volume fails suddenly e.g. because of a power failure or cold-restart.
Anyway, under all circumstances if you don’t want to lose your data, do NOT install another system like Ubuntu on the same hard drive, this can overwrite your data and they might be lost forever.
Your best chance to recover all of your data is:
1. Download a copy of Knoppix or another OS that can boot from CD
2. Download data recovery software that you can start from command prompt
3. Insert Windows 7 DVD, open a command prompt as described above and then recover your data
ZAR does not seem to support data recovery from command prompt, I’ll have to look into this to find a data recovery software that actually supports it.
EASY solution:
The easiest solution would be to add the hard drive to another computer (of a friend?) and then use ZAR to recover your data, then reformat and re-install Windows 7.
Luckily, I didn’t have a missing operating system error for a while and I try to avoid “hard” reboots. If you want to avoid problems in the future, always try to shutdown your PC the normal way.
Thanks for the response. I am currently booting Ubuntu from a CD. The only problem is, I need to install the driver for my wireless adapter in order to get online and the one disk drive I have is being used to run Ubuntu. Is there any other way I can install my driver for my wireless adapter without going on Ubuntu? Or is there any data recovery software I can get access to without going online? And once you look into it, any data recovery software you might suggest? One last question, will recovering my data on the command prompt fix the missing operating system error or only fix my RAW disk? Sorry for all the questions or if I sound stupid. This is just a topic in which I do not have much/any experience. And, now if I recall, I have been abusing hard reboots as of late. Thanks for the advice.
Sorry for this omission. In my last post I failed to mention, Linux OS does not support my wireless adapter’s drivers, I can move my desktop to a wired connection if necessary (although that would not be optimal), and I do have the option of transferring the data recovery software over to my computer via flash drive.
Sorry for the late reply.
You currently have access to the internet, so all you need to find is a data recovery that allows you to recover data from command prompt.
If you recover your data, this does not mean that any of your problems will disappear. You will still get the missing operating system warning and your disk will still be in RAW format. However, you have a backup of your data then, so you can FORMAT your hard drive and re-install Windows 7. This seems to be the only way to fix your problems right now (someone please correct me if I am wrong).
Unfortunately, I don’t know any data recovery software that does support command prompt recovery and you would still need a second drive to backup your data to. So my suggestion is to get a 2nd clean hard drive, install Windows 7 and then use ZAR to recover your data.
However, I would try to call the customer support and/or ask somewhere else to get some more opinions on this. Maybe there is a chance to you can get fix your RAW disk and then get rid of the missing operating system error, but I doubt it.
I also recommend to a create a “Windows 7 Recovery Disk” after re-installing Windows 7, might help to avoid trouble in the future if you get the missing operating system error ever again.
Also boot disks might be a topic of interest. Some boot disk include tools to recover data, hopefully you will find a free boot disk that provides data recovery tools here: http://www.bootdisk.com/
Here’s a paid boot disk that provides data recovery tools: http://www.livecd.com/
You can burn this CD then boot from it and recover your data. When you’re done with your backup, format and re-install Windows 7.
Hi, I encountered this ‘Missing Operating System’ message today after I over clocked my CPU and over wrote the settings to my CMOS profile. After a reboot I got the message. I freaked out, the first thing I did was optimized my BIOS default and rebooted it but didn’t help I got the same message. I went online and came across this troubleshoot but I can’t get past the ‘System Recovery Options’ there’s no window prompt like the one in the picture that scans the hard drives for an OS, so I have no OS list to choose. Why is this???
Hi. I installed multi os in my laptop. That is
c: Windows 7-64Bit
E: Windows7-32 bit
Now Windows 7 62 bit is corrupted in partition C. Now i Formatted Partition C and put new os Widows7 64 Bit. At the Same time i have all the files of Windows7 32-bit in Partition E. but the boot loader doesn’t show the os.
how i get The os in E: in my boot loader..?
Pls reply to my mail [email protected]
Thanku in advance for ur help.
Hi..Everyone.
I have just saw the phrase “Missing Operatin system” on my computer for I think the second time on my computer. Acer with Windows 7. I really have important files that I don’t want to loose. But I tried pressing the F2 & some other few stuffs I can’t remember.
Please I need help cause…I might see this message leading to more damage..
i have tried running the chkdsk c: /f/r thing but when it got to stage 5 of 5 it said “failed to transfer logged messages to the event log with 50” and then it had the x:/source>
what am i meant to do now??
i seriously have no idea what to do, its starting to frustrate me D:
Prexxy, have you tried recovering your PC with the Windows 7 DVD? You can always install Windows 7 on another partition if you have one and then copy your important data. If that doesn’t work you need data recovery software. Read through the comments, it’s all there.
KL, the only solution is to reinstall Windows 7. Make a backup of your files (possibly connect the hard drive a 2nd PC to get the important files).
Hi guys,
when I do a “bootrec /rebuildbcd” it will find the WIN7 installation allright and will ask me to add it to the “start list”. When I reply “Yes” the message is “Element not found” (I’m sorry, it’s all in German; do hope you can make sense of my somewhat clumsy translations …).
Any input for a clueless guy in Hamburg?
Thanx in advance.
I get “Missing Operating System” when I boot and can’t access anything (no Bios no command prompt). I am using Windows 7 32-bit Ultimate. Can I use Dell OEM Windows7 Professional Disc to fix this issue? I don’t have any other OS disc. Please please reply
Yes, I’d try to use the DELL OEM Windows 7 DVD. I used a OEM DVD recently and it worked flawlessly .. you’ll only could get into trouble when you’re reinstalling Windows 7 because DELL uses OEM keys to activate Windows 7.
Btw, you must be using the wrong key for the BIOS, check your manual.. if you can’t start your BIOS you might have another more severe problem.
Hello
I dont think anyone so far have had this kind of problem…
I had to remove the CPU fan and then put it on again because my processor was overheating, because one screw of the fan was loose, i also checked if the cpu chip was correctly installed in the motherboard
Then, i open my pc, everythings works fine.. i make a little update on my anti-virus… asks me to restart my PC….ok
At restart, i get the missing operating message for no reason
PANIC !!
i go in the bios to check the boot priorities… i see my thumb drive is at 1st priority… im like wtf… i remove it and put my HDD in 1st priority
Then, i close and open my computer, same problem, the missing operating system message
I have 2 500g HDD in RAID 0 with some information id like to keep
Im a bit lost…. what do i need to do first ? do i need to do a data recovery ? or just use my windows 7 64 bit cd and do the chkdsk thing ?
Also, how do you do a data recovery on a Raid 0 ?
thanks for the help !!!
olivier, I’d try to fix the master boot records as described above first. So, insert your Windows 7 DVD, change boot order in your BIOS to DVD drive, run command prompt and enter the commands. If you’re lucky this will already resolve the missing operating system error.
As for data recovery on a raid drive it should work like a normal data recovery. I suggest to do further research on the subject before your proceed with data recovery.
i had the same prob. but it seemed to happen when i had a usb memory stick in when i powered up. new pc so was a bit disturbed.
took it out after turning off, then powered on again and it worked okay. !!!!
i have the same problem. I tried to follow your post, but even after setting boot sequences, I still get same problem. Boot starts but don’t reconize any drive, therefore I don’t have a drive I can boot from. Test have said both hard drives are good no issues. I have xp on c: And windows 7 on G:.
I did it all – no result….
Until i realized that a USB disk was pluged. Bios is now corrected. 2 weeks of troubleshooting and a new harddrive is wasted. BUT problem solved
I tried this, and it worked until my computer had to restart for an update. It took me right back to the error message again.
I was attempting to remove malware on my Window 7-64 bit and got frustrated and tried to start computer in safe move (F8) it didn’t open safe mode, but I got the missing operating system file. I have done all the above. I am able to get into windows repair, by inserting the win7 disc and changing to dvd to load. I have back up and system mirror of files. When I go to command prompt the C: drive is the boot drive and all my files and system files and on the D: drive. X drive is suppose to be the boot drive. chdsk /f/r/ ran fine and finds no errors. I would reformat but some programs have no disc they were installed via internet and I can get them back if necessary. Any suggestions on the files being on D instead of C:?
I definitely ran into the problem because of hard discs being connected, I had about five plugged in, and upon unplugging them it worked like a charm.
hi there. I’ve been following these instructions.
repair could not fix.
fixmbr provides a “vol does not conain a recognized file system ”
msg.
I was upgrading a CPU. When I swapped the CPU pc would boot to black screen. I then popped the bios battery and rebooted no joy.
I then put old cpu back in and got the missing OS error msg….any help appreciated.
I woke up this morning to that darn message “missing operating system”. This is the second time that I’ve seen this message. I had to close it down 4 times before it finally came up. I just wrote HP telling them that I need the Windows 7 DVD just in case I do need to reinstall it. I don’t understand why these stupid companies don’t give the DVD with the tower. Could I use the recovery disks to get Windows 7 working again? Or do I need the Windows 7 DVD?
I was about to suicide!
I reinitialized my work laptop for updating, and i recieved this message…
Ad its a company laptop i dont have any windows 7 dvd (i’m pro-xp) and i started reading the coments… and then i realized i had the f…. pendrive conected and the computer was trying to boot from there….
Thanks a lot for your unestressing words!!
I don’t know if anyone else listed this solution, but I’m too lazy to read all the posts. I ran into the “Missing Operating System” issue the other day after a 2 day blackout due to severe storms. I was flipping out, nothing helped to fix this (I tried all the solutions I could find) and then a really simple idea hit me. I check my BIOS settings, and sure enough, the power outage had caused the BIOS to revert to it’s default settings. I use a RAID-0 array (If you don’t understand RAID-0, it’s when two drives act as one, (Stripped mode or performance mode) and data is stored ACROSS both drives for faster loading) Because the BIOS default is not RAID mode, my PC could not detect a full installation of windows, as part of windows in one one drive and part on the other. Once I set my BIOS back to RAID mode, everything was back to normal. I hope this information is helpful to someone else in the same situation.
(Nice work on those other solutions though!)
You also want to make sure your boot priority is set to your hard drive and that you don’t have a flash drive plugged in. :)
Thanks for the post, Wachinagi. I spent over 4 hrs trying to research how to correct my ‘missing operating system’ problem. The settings were not on RAID. Changed that and my computer restarted normally.
We had that message this morning.
No Windows 7 DVD came with the Toshiba laptop.
After turning off and on a couple of times with no luck, we removed the battery and put it back in. Thankfully that helped solve the problem for us.
Thanks, this helped. Ended up being because I had a usb flash drive connected. I guess it was trying to boot off of that.
You could just press F8 to tell your computer not to boot from the USB stick…..
I felt so stupid when i realized this was the problem with my computer :P
Just a quick Q, If your not sure of what bit the computer is running like 32bit or 64bit. if the OS was 32bit do you need the recovery disk to be 32bit or will a disk with 64bit be ok to use. Windows 7 btw.
Eire, there are 32-bit and 64-bit recovery disks, so you will need the correct one for your system. A 32-bit disk won’t work for the 64-bit OS and the other way around. Same goes for Windows 8. If you download one from the net instead of creating one make sure its the correct one.