I have running windows beta build 7000 and i have removed watermark but now compatibility mode does not work. How can I restore watermark? I don't have a system restore point.Did you edit the registry to do this?

I'd save data and rebuild and restore data back as a quick solution if this has to be fixed right away. Otherwise we can help here plug away to a solution hopefully.Hello.

To remove the watermark from Windows 7 beta builds, you must USE a resource editor to 'patch' a system file. I am assuming that since you don't know what file to edit to get it back, you used a third party patcher

Luckily, most patchers make a backup of the system file edited.

First look for a backup in %systemdrive%\User32Backup\ (ex. C:\User32Backup\)
You should be looking for 'user32.dll.mui'
If that folder does not exist CHECK in %windir%\System32\en-US\ (ex. C:\WINDOWS\System32\en-US\)
You should be looking for 'user32.dll.mui.bak'

If you FIND EITHER of those files, simply replace the 'user32.dll.mui' file that is currently in %windir%\System32\en-US\ with one of the backup copies, restart, and report back here.

Thanks and good luck.