Missing disk space in Windows XP

Solution 1:

Lenovo installs a pretty useful application called "Rescue and Recovery" on most of it's systems. This applications performs full scheduled backups of your system to your hard drive, which you can access on boot by pressing the "ThinkVantage" quick-key on your keyboard.

Most probably the used space that windows is reporting incorrectly is the hidden portion of the disk that Lenovo's software is using up.

Search for Rescue and Recovery in "C:\Program Files\Lenovo\Rescue and Recovery" and start up the application to check for the backup regime that's running.

You SHOULD also be able to access the software from the Control Panel under "Lenovo's Enhanced Backup and Restore".

Good luck!

Solution 2:

Just had the exact same problem with a Lenovo laptop. I was able to fix the problem after reading akseli's response. The Rescue and Recovery backups were occupying 24GB of the 61GB partition.

If you have a hidden folder called either C:\RRtemp or C:\RRbackups then this is where the hidden data is stored. WinDirStat cannot access the folder, so it fails to report the data.

Solution 3:

On the same property windows, click on the second tab, then Check Now. Check the "Automatically fix file system errors" box, then Start.

Solution 4:

Another possibility is that the "extra" space is consumed by ADS or files hidden by some rootkit or other

from here on is an edit: ADS == Alternate Data Streams
How to locate:
http://www.irongeek.com/i.php?page=security/altds

Solution 5:

I've seen a similar issue where VSS was taking up a lot of the disk. Try running this to see if it tells you how much space VSS has.

vssadmin list shadowstorage

Also, make sure you're running WinDirStat with Administrator rights, otherwise it can't see everything on the disk.