Here's yet another program that promises to clean up and optimize your Registry. But given that there are plenty of Registry cleaners available for download--some free, and some for pay--there's no reason to use RegVac Registry Cleaner ($30, 3-day free trial). It lacks a very basic and important feature that even free Registry cleaners offer.
Other Registry cleaners first scan your system, then show you the results, and then ask which errors you want to fix. RegVac Registry Cleaner, however, instead scans and cleans, and then shows you the work it has done; you can't pick and choose what to fix. You can tell it to undo some of the changes after the fact, but it's much better to first put the decision in your hands. In addition, unlike other Registry cleaners such as CyberDefender Registry Cleaner, it doesn't give you details about the Registry keys that need to be fixed. It also lacks the features of another cleaner, RegistryBooster 2010, such as defragmenting the Registry.
If you want a for-pay Registry cleaner, either CyberDefender Registry Cleaner or RegistryBooster 2010 is a better bet. They're comparable in price to RegVac, and they offer more. And for freebies, CCleaner has an excellent Registry cleaner as well.