How to Free Up Space After Installing Vista SP1
Installing the Windows Vista Service Pack 1 update can take quite a bit of time. The download alone is over 400 MB. Depending on your internet connection the download and installation of Vista SP1 will take a little patience. But since the update addresses quite a few issues with Windows Vista, it is worth the time.
Once you have downloaded and updated SP1, you might not have noticed that the free space on your hard disk has reduced more than expected. The reason for this is that the SP1 update makes a backup of all files that are replaced in the installation. This obviously allows for a reversal of the installation in case of problems.
But what are the chances of reverting back? How many times have you uninstalled a Windows update, let alone a complete service pack update? If your answer is never or hardly ever, you might want to consider removing the backup files. All in all this can free up over half of gigabyte of hard disk space.
The Vista service pack 1 update actually installs a little program that enables you to remove the backup files. Simply click the Start menu and type “vsp1cln.exe” in the Start Search box. Press Enter to execute the application.
If you have the User Account Control enabled, you need to click Continue to proceed.

Start the cleanup process by pressing the Y-key. Do not wait for a completion message, the screen will automatically disappear once the cleanup is done.
On our Vista test machine, the actual space freed up by this action was 800 MB!

Once you have completed the removal of the backup files, consider running a disk defragmentation program to optimize your free space.
