Your PC is full of crud, junk, and gunk that harms performance, clogs up your hard disk, and makes system crashes more likely. Some of the junk came with your PC, but much of it has accumulated over time, as a result of installing and uninstalling programs, surfing the Web, and creating and saving files.

But things don't have to be that way: Downloadable software can clean up your PC and give it a new lease on life. Check out these 20 files that will do the job--your PC will thank you for it.

General Cleaning Tools

We'll start first with some broader or wider-ranging utilities; there's some overlap in what they do, but half the fun is trying them out.

PC Decrapifier

You buy a shiny, brand-new PC. You expect it to be clean, lean, and mean. Wrong! Buy any new PC, and you'll find it full of "craplets"--software installed for no reason other than that the PC maker gets paid to put it there. These craplets slow down your PC startup and its general operation.

The free PC Decrapifier removes dozens of craplets automatically. Using this program is exceedingly simple. Just run it, and it does its removal work automatically. Don't expect it to completely clean your PC, because it removes only a specific set of craplets and trialware programs--namely, those that are specifically put on new PCs, such as QuickBooks Trial, Wild Tangent Games, Dell URL Assistant, and many others. For a full list, go to the developer's site. Note that when using this program, it's a good idea to tell it first to create a restore point--as illustrated in our screen--just in case it removes something that you wanted to keep.

Download PC Decrapifier.

TuneUp Utilities 2007

This all-in-one program costs $40 but has has just about every degunking and clean-up tool you could name. Looking to remove unneeded files from your hard disk? It'll do it. Clean up and optimize your Registry? It's in there as well. Perform an overall system optimization? Yes, it does that also, and plenty more as well, including controlling which programs run on startup, and even undeleting files--or completely destroying files, if you want to protect your privacy.

Download TuneUp Utilities.

WinSettings Pro

This all-in-one system cleaner costs $50 but includes a slew of extra features. It'll find and remove junk files, duplicate files, and Internet history; it also comes with a very nice cookie cleaner that shows you every cookie on your system, including each one's contents, and lets you delete the ones you no longer want. It has plenty of features beyond system cleaning, including a variety of Registry tools that claim to speed up Internet access, and tools for a variety of other tasks such as customizing Internet Explorer.

There's more, such as a screen capture program, a wallpaper randomizer, and pretty much everything but the kitchen sink. By itself, it's not the best system cleaner, but for those who want the other tools as well, it's a good bet.

Download Winsettings Pro.

Super Utilities

Here's another all-in-one tool for cleaning up and optimizing your PC, and it too features a load of extras. You'll find a startup organizer that shows you what programs start automatically when you turn on your PC, and lets you disable them. There's also a Registry cleaner, defragmentation tools, antispyware features, and much more--27 tools in all.

This program is shareware, and there's only one drawback to it--at about $60 for registration, it's not cheap. Still, it's worth trying out for free, and after 30 days, you may decide that it's worth the price for registering.

Download Super Utilities.

Magic Utilities

This simple, straightforward suite of utilities gives you five different tools for cleaning your PC--one for uninstalling software, one for organizing or killing programs that run on startup, one for finding junk on your hard disk and letting you delete it, one for shredding files, and one for killing any running processes. There's nothing fancy or flashy here; it's just simple and easy to use. This shareware offers fewer features than suites like Super Utilities, but at $40, the registration fee is lower as well.

Download Magic Utilities