is there any other way to change OS interface without logging off?
aside from this steps
Install New Multilingual User Interface (MUI) in Windows 7 Ultimate:
1. Start -> All Programs –> Windows Update –> Optional Updates.
2. Open optional Updates and go to the section Windows 7 Language Packs.
3. Tick the Multilingual User Interface (MUI) you want and click OK
4. Proceed with Install Updates
How to change the Windows 7 Display Language:
1. Go to Start -> Control Panel -> Clock, Language, and Region / Change the display language
2. Switch the display language in the Choose a display language drop down menu.
3. Click OK
4. Log off for the changes to take effect (This will affect only the user profile under which you are currently logged on).
