Ace Utilities could be the way to go. It is free to use for awhile and very thorough. Not very gimmicky either and has a lot of options which I have found useful. (Find duplicate files in drives/folders, clear empty folders, Clean registry... you might want to check it out. I don't own the full ver. but needed it to clean up my music collection. The registry cleaner seems pretty thorough.
Registry is the centre database of your computer operating system which contains information and settings for hardware, operating system software, most non-operating system software, and per-user settings. You must load the registry whenever you launch any programs on your computer. If the registry is too fat or with some errors, computer’s performance will seriously be impacted.
To optimize your registry, there are 2 ways.
The first way is to clean your registry manually. But it is with high risk to do this if you are not a registry expert. The wrong deleting or modification in registry will lead a computer crack. Click the "Start" menu button to open the Start menu. Click "Run" Type "regedit" into the text field and press "Enter". Access the many different entries in your Windows XP registry. It is separated into primary sections: HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS and HKEY_CURRENT CONFIG. Click the plus to find and delete entries in the registry that you know are either causing conflicts or no longer necessary.
The other way is to download a Link Removed due to 404 Errorand scan your registry for free. If you are not familiar with registry, it is highly recommended to use Registry Optimizer.
The Registry is the heart and soul of every Windows operating system. What this means in practice is that editting or deleting the registry manually is not only a daunting but also a risk one. Especially to the computer newbies, it is sometimes impossible to keep clear of mistaken deletion. I strongly suggest that the computer newbies users some advanced registry cleaner to guarantee a safe registry enviorenment of Windows.
There are lot of tools you can choose, you may try to have a search
or you might find the answers to your questions in this page: Link Removed