You can reduce the Microsoft Windows 7 WinSxS folder’s size by about 3GB, on average. On my x64 system I went from 10.3 GB to 6.6GB. The process is extremely simple.
Enter the command prompt:
Winkey+R > cmd.exe – make sure you’re using it with Administrator privileges. You may need to find cmd in the Start menu and right click > Run as Administrator).
dism /online /cleanup-image /spsuperseded and hit enter.
And you’re done!
Note: this is only useful for Windows 7 users who installed the Service Pack updates themselves. If your system came with SP1 already installed, this won’t do anything.