I've recently encountered some problems with a driver with the file extension .sys and had to do a registry clean in order to remove a Blue Screen error. Now while registry cleaning seems to be the answer to everything: system errors, unknown file extension and faster boot up of PCs, it could also be the cause of some problems especially if you inadvertently deleted some important registry files.

However, how can you ever get to being a "techie" if you're afraid of "messing up" your PC, right? The thing is, almost all registry cleaners will backup your registry so if ever you deleted an important registry entry or deleted a file with an unknown file extension but it turns out it's an important file, all you have to do is restore the backup before you deleted the entry. And of course, there's always Windows System restore.

So, are registry cleaners safe? The answer is it depends. Be sure that the registry cleaner can backup your registry otherwise, it's a useless software.