Windows Vista has quite a large footprint in terms of disk space. Sometimes even after uninstalling unused programs and deleting files you still may find yourself low on space. Therefore I put together these tips that will help you regain control of your hard drive:

1. Use the Disk Cleanup Utility. This utility has been around for a long time but it seems like people have forgotten about it. You can run the command by typing cleanmgr.exe from a command prompt.
2. If you installed SP1 then you can run the vsp1cln.exe. After you install SP1 a lot of files are left on your machine in the event that you want to uninstall it later on. However, most people never do this. Running vsp1cln.exe can reclaim anywhere between 1-3 gigabytes of space. You will need to run this utility as an administrator.
3. If you have a desktop then you may want to consider Disabling Hibernation. Hibernation can chew up a lot of space. When your machine hibernates, everything in memory is flushed to disk. If you have 4GB of ram then hibernation will cost you ~4GB in disk space. Hiberation can be disabled by running the command:

   "powercfg -h off"

4. Cleanup System Restore - Whenever you make a major configuration change to your computer Vista will automatically create a backup copy of your system files so you can reverse the changes later on. Although these files can be cleaned up by using the Disk Cleanup Utility there is a pre-allocated amount of space that Vista dedicates to these files. In some cases, you may have your own backup solution like WHS so you really do not even need this functionality. On my home PC I saved 14GB of space by shrinking the pre-allocated space reserved for these files down to 1GB. This can be done by running the command:

   "vssadmin Resize ShadowStorage /On=C: /For=C: /MaxSize=1GB".

   Just remember that changing this setting can affect your ability to restore from a crash later on. So if you change this setting make sure you have an alternate strategy.
5. Use windows search to find files over a certain size. This is a great way to find log files or other temporary files which are no longer needed.

Hopefully these tips will help you reclaim some space on your PC. Just remember changing some of these settings could have adverse affects so make sure you understand the consequences first.