I deleted Windows\Installer folder, is there a chance to repair?

I accidentally deleted the Windows\Installer folder in Windows 7. Is there a way to repair this, because I can't install new Microsoft software anymore.

Try recovering the files using a Shadow Copy (Previous Versions). If your edition of Windows doesn't expose the Previous Versions tab, use the free ShadowExplorer to do it.

If that doesn't work, recover from backup.

If you don't have a backup, you're in big trouble.

The only real options you have at that point are reinstalling Windows (and all of your applications that use Windows Installer) or, maybe, trying to use the msizap.exe command line tool to reset all the Installer's registry information.

You can't reinstall it, because actually version 5.0 is not redistributable.

The simplest solution is to copy the folder from an other Win7 computer.

Open an elevated command prompt and type:

sfc /scannow

http://support.microsoft.com/kb/929833