After installing Service Pack 1 for Windows Vista a lot of older and unnecessary files are left on your computer, taking up valuable space on the hard drive. Although these files are no longer needed by Windows Vista, they were required by the first release of Vista. SP 1 does not remove these files in case you wish to uninstall it in the future. If you want to free up the space on the hard drive by removing these files, and you are certain that you will not need to uninstall SP 1, then follow these steps to clean up the unnecessary files.

Note that removing these files will mean that you will not be able to uninstall Service Pack 1.

Open the Start menu, type in cmd and press Enter to open up the command prompt.

At the prompt type vsp1cln.exe and press Enter.

Thanks Mike.

Nice little tip, I just got back 0.7 GB of wasted space.