What Is Disk Cleanup?
Disk Cleanup is a computer maintenance utility that is included in the Microsoft Windows operating system and it is designed to free up space on the hard drive. The cleanup process involves searching and analyzing the hard drive for files that are no longer needed. Then it proceeds to remove them and thus freeing up disk space on the hard drive.
Here is the list of all the files that can be deleted for Windows XP:
Downloaded program files.
Temporary Internet files.
Web client/publisher temporary files.
Compress old files.
Catalog files for the content indexer.