The older your PC is, the more junked-up its Registry becomes. Badly written programs (and plenty of those are around) don't bother to clean the Registry when you uninstall them, and some applications add unnecessary junk. The messier the Registry is, the more likely it is to crash your PC or slow down its operations. Though the benefits of using a Registry cleaner are often debated, these utilities might be worth a try.
Wise Registry Cleaner
This freebie scans the Registry, flags orphaned or bad entries, and identifies entries that are either dangerous or safe to delete. Like most Registry cleaners, the utility will back up your Registry so that you can restore it if need be.
Download Wise Registry Cleaner | Price: Free
Glary Registry Repair
Here's another very good, free Registry cleaner. It lets you choose which changes to accept and to ignore, and creates an Undo file so that you can revert to the previous version of the Registry if problems occur.
Download Glary Registry Repair | Price: Free
Registry First Aid
If you're willing to pay for a Registry cleaner, this is a great choice. Longtime PC World contributor Steve Bass rates it as the best Registry cleaner, with good reason: It does an excellent, thorough job. It also searches the Internet for details about Registry keys, so you can have background information before deciding whether to delete or change them.
Download Registry First Aid | Price: $28 (Trial)
Auslogics Registry Defrag
Cleaning your Registry may help keep your system in tip-top shape, but you can do something else for it as well: Defragment it. This program shows how fragmented your Registry is, defragments it, and restarts your PC. The program also creates a restore point so you can restore the Registry if necessary.
Download Auslogics Registry Defrag | Price: Free