1. The Disk Cleanup (Cleanmgr.exe) tool includes one confusing option that can leave an inordinate amount of wasted space on you hard drive. When run, one of the available options offers to delete Temporary files. Unfortunately, this option may display a value of zero even if your Temporary folder contains hundreds of useless files since this value lists only file in that folder with a date more than one week old. Therefore, if files still exists after using the tool, you may at your convenience delete any and all files unnecessary.
2. The article [Q310312] states the Disk Cleanup tool helps you free up space on your hard disk by searching your disk for files that you can safely delete. You can choose to delete some or all of the files as follows:
Remove temporary Internet files.
Remove downloaded program files. For example, ActiveX controls and Java applets that are downloaded from the Internet.
Empty the Recycle Bin.
Remove Windows temporary files.
Remove optional Windows components that you are not using.
Remove installed programs that you no longer use.
Note: If you start the Disk Cleanup utility and click the Disk Cleanup tab, a System Restore: Obsolete Data Stores entry is available. These are files that were created before reformatting or reinstalling Windows, and are obsolete and can safely be deleted. If you choose to cleanup and delete these files, you will no longer see them or this mentioned option again.
3. The article [Q315246] describes how to use command-line options to configure the Disk Cleanup tool (options) to automatically clean up certain files by using the Scheduled Tasks tool.
4. The articles [Q812248] and [Q812930] state the Disk Cleanup tool may stop responding (hang) and you may receive the following message -- that would require an edit of the system registry to correct.
Disk Cleanup is calculating how much space you will be able to free on (C:).
This may take a few minutes to complete.
Scanning: Compress old files
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\VolumeCaches\Compress Old Files
Note: Two important things to know is that the system registry copies changes immediately and there is no Undo command. The editor does not wait for a Save to be issued since it does not have one and therefore makes changes permanent as they happen -- you make a change it's gone forever unless you remember it or have already backed up a copy. Use the editor sparingly and soberly and do not leave it open unnecessarily.
a. Click Start, Run, type regedit, and then press Enter.
Note: Click the "Plus" before each of the words preceded by a back-slash in the above registry address until you reach Compress Old Files, which you will then bold/highlight by clicking.
b. From the Main menu, click Edit, Delete, or after an entry has been bolded simply press the Del key on the keypad and respond with an affirmative.