As useful as registry cleaners can be, they do have their limitations. Unfortunately, not everybody understands these limitations. For example, since registry cleaners generally only look at a computer’s registry, its usefulness is constrained by the amount of critical information that is contained in your registry.

So, with that in mind, what can’t a registry cleaner do to your PC? Well, since malware is not usually stored in your registry, cleaning out your registry is not likely to fix any spyware problems that you may have on your PC. Put simply, these programs are not designed for malware removal.

Furthermore, if your registry is corrupt, usually the only way to fix it is to use a previous system restore point. By selecting the ‘last known good configuration’ for your PC, you can usually fix the problem. However, this solution has nothing to do with registry cleaners.

The Windows registry is also not used by virtualized applications, which circumvent the limitations of an operation system to make certain programs run on a specific computer. Registry entries for these programs are found online, or in another location, not in the Windows registry. When registry cleaners examine virtualized applications, they may find that a registry key is not present, which could confuse the program and cause adverse effects to your PC. While registry cleaners are very safe in a standard, end-user system, they are best avoided on a system that exists in a virtualized environment (like running Windows from Boot Camp on an Apple computer).

Nevertheless, registry cleaners do a lot of good things to your PC. By removing outdated, unnecessary registry entries, they can help smooth out your PC’s performance, or make certain applications run more efficiently. Often, these performance benefits rely on the quality of the registry entries removed, as opposed to the number: since there are millions of entries on your computer, removing even a few thousand of them is not guaranteed to generate significant, noticeable benefits.

If you understand the limitations of registry cleaners, then you can avoid scare-ware products, which trick you into buying a program that you don’t need. For example, certain viruses may create a pop-up on your computer that claims to fix your PC’s spyware problems by cleaning out your registry…but only if you buy a certain, expensive cleaner. These programs are scams, and you should always be wary of submitting your payment information to anyone on the internet.