As you install and uninstall programs, browse the Internet and download to your computer, several unneeded, obsolete, and sometimes dangerous files accumulate on your hard drive, taking up disk space and slowing down your computer. These are everything from temporary (*.tmp) Internet and computer files, off-line web pages, deleted files in your recycle bin and other unnecessary files. You can recover valuable disk space by getting rid of these files, and help speed up system performance.