A hard disk cluttered with stuff you no longer need may or may not be an impediment to performance (it certainly can be if the disk is home to a page file), but it’s a nuisance at best. If a volume is running short of space, you can tidy up a bit with the Disk Cleanup wizard. Open Computer in Windows Explorer, right-click the disk in question, and choose Properties. Then, on the General tab of the properties dialog box, click Disk Cleanup. You’ll be given the opportunity to choose between cleaning up your own files only or all files on the disk (including those created by other users). You’ll need administrative credentials to go for the latter option.