ion to restore a deleted Registry entry, restoring might not be possible if the DLL entry you just deleted is essential for your system to boot.

7. Once you give the tool the go-ahead and it starts removing Registry entries, walk away from your PC. Play with the dog, have some coffee, or watch TV. This is for safety purposes: If you're fiddling with the PC--moving the mouse, deleting desktop shortcuts, whatever--you're making changes to the Registry while a Registry cleaner is working. Not a good idea.

8. If you discover a problem (for instance, maybe Excel no longer launches), don't panic. And don't do anything aside from using the Registry cleaner's restore feature, which ensures that only the changes the program just made are reversed. That will probably fix the problem. If not, the next step is to restore the Registry with ERUNT, the tool I mentioned in step 3. As a last resort, restore your PC with a backup program--which you certainly have, right?

9. You needn't perform a Registry scan more than once a month or so, especially if you don't often make changes to your PC. Scanning more frequently won't hurt anything, but you're unlikely to see a significant performance boost.

10. Are you a techno-fanatic who needs the Registry to be squeaky clean, with absolutely no stray entries and trimmed of all fat? There's no harm in using multiple freebie Registry cleaners--provided you use them one at a time. You might also want to select a Registry cleaner (such as jv16 PowerTools or Registry First Aid) that includes a defragger, or choose a free defragger such