This tip will show you how to create an unattended disk cleanup which will also empty your prefetch folder. This tip assumes you have Windows XP installed in c:\windows.

Step 1.
Create a new text file and place the following contents inside:

c:\windows\system32\cleanmgr.exe /dc /sageset: 1
c:
cd \
cd c:\windows\prefetch
del *.* /q

Step 2.
Save the file, changing the extension from .txt to .bat
For this tip's purpose, we will call it clean.bat

Step 3.
Execute the file. This will run the Disk Cleanup program in a special mode which asks what items you will want cleaned when Disk Cleanup performs an unattended cleanup. Check the items you wish to have cleaned up, then click OK.

Step 4.
Right-click on the clean.bat file and click edit. Change the first line to read:

c:\windows\system32\cleanmgr.exe /dc /sagerun: 1

Step 5.
Save the file. You can execute this file in place of running Disk Cleanup, or, to have this program run unattended, run the Add Scheduled Task Wizard in the Control Panel and create a scheduled task using the clean.bat file you just created.

Note: This cleanup script will also clear windows prefetch directory. Often this directory can become cluttered with old appication and a cleaning would free up disk space but it will result in a one time performance decrease and windows has to rebuild the cache with active software afterwards.