Switch between languages in Windows 7 Ultimate / Windows 7 Enterprise
Tip: If you use the Windows 7 Anytime Upgrade you can upgrade to Windows 7 Ultimate and then download all language packs via Windows Update and install them comfortably on your PC.
1. Step Type %SYSTEMROOT%\System32\lpksetup.exe into the search field on your Start menu.
2. Step Click on lpksetup
3. Step Browse to the language pack that you downloaded for example via MSDNAA.
4. Step Click on next (will only work on Ultimate/Enterprise)
5. Step When the installation is done, simply click on change display language.
Switch between languages in Windows 7 Home / Professional
Apparently, Microsoft allows you to download the language packs from their Update servers. So first you’ll have to download the language pack that you need and then proceed with the next steps.
Tip: If you are a TechNet subscriber or have access to MSDNAA you can download the Windows 7 Language Pack DVD for free.
1. Step Open an elevated command prompt
2. Step dism /online /add-package /packagepath:C:\insertpathtolbcap\en-US\lp.cab
3. Step bcdedit /set {current} locale en-US
4. Step bcdboot %WinDir% /l en-US
5. Step Delete old language pack registry key. Open the registry editor and go to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MUI\UILanguages\
If you want to example switch from German to English, you simply delete the folder de-DE after creating a backup of the registry keys.You can then switch between languages quite easily. Simply keep a copy of the registry keys somewhere and repeat steps 3-4 again using the locale of your desired language, e.g. de-DE, en-US, th-TH, tr-TR, etc.