If you are using Windows OS that has the "System Restore" feature enabled, over time as it creates and saves checkpoints it can tend to take up a big chunk of your hard-drive space. By default when having System Restore feature enabled, it seems to take up a crazily high percentage of your total hard-drive space.
You may want to adjust the settings so System Restore uses less hard-drive space:
Click Start . Right-click on My Computer and click Properties . (or Right-Click "My Computer" icon from desktop)
In the System Properties box, click the System Restore tab.
Verify Turn off System Restore on all drives is not selected.
Select (Click) the Settings button then Under Disk space usage, move the slide bar to the left to decrease the amount of disk space reserved for System Restore . Click Apply and then click OK .
Also, if using Internet Explorer, you may want to try deleting old cached files:
From IE Browser click on "Tools", "Internet Options", then under the Temporary Internet Files area click the "Delete Files" button, then Check-mark in box to "Delete all offline content" then "OK" everything.
You may also want to run a defragmentation on your hard-drives (see my link before for more info):
For more tweaks, tips, tricks, security, freeware utilities, games, and various other software and resources, please visit my blog, "Tweak My Computer" at:
http://tweakmycomputer.blogspot.com/