If you think about it, there are literally tens of thousands of files on your computer. And each time you install a new application, even more files get added. On top of that, there are all the documents, graphics, and Web pages not to mention graphics the you have collected or created. No matter how you look at it, there's a lot of clutter on your computer.

Worse still, often programs thought you'd gotten rid of often leave bits of themselves behind. These are in the form of "dead" files that aren't used by any other application but which still take up hard drive space.

You can do without a number of the files littering your hard drive. The problem is knowing which files you can safely delete.

Why Not Just Delete Them?

Opening Windows Explorer, highlighting an offending file, and pressing Delete is very tempting. And it can be very dangerous. The file you zap might be one that Windows or one of your applications needs. Without it, the program or even Windows itself may not start properly or at all. Or, you might send the only copy of a document you need for work or some other important reason into digital oblivion. Having to recreate it from scratch can be difficult or, more likely, impossible.

Indiscriminately deleting files can cause problems with the Windows Registry. The Registry is a database that stores software configuration information. When many programs are installed, they add information to the registry. The more software you install, the larger the registry gets. Windows constantly reads the Registry, and having useless entries just slows everything down.

But with a little knowledge, and some care, you can safely delete the files that you don't need.