After each test, we restored the systems to their original state of disarray with Acronis TrueImage. We also tried to determine whether the system seemed friskier post-cleanse. We tried each tool on three computers: a messy work PC using Windows XP SP3, on a pristine Fujitsu Lifebook T-Series laptop running Vista, and on an old ThinkPad laptop.* We ran the registry scan and repair module of each application, rebooted the system, and watched for problems that would indicate that the “cleaning” process broke something. We examined two free products (Advanced Windows Care and RegSeeker) and three commercial ones (jv16 PowerTools, Registry First Aid, and RegSupreme Pro). To find out which registry cleaner catches the most errors, is the safest and easiest to use, and (just as important) creates the fewest hassles, we tested five popular registry cleaners, many of which came recommended by PCWorld readers. It also depends on the effectiveness of the registry cleaner you choose, and there are a lot to choose from. That’s right, a big, fat perhaps-because everything depends on the condition of your registry. The answer is, emphatically and unequivocally, maybe. The big question we’re asking in this piece is whether a registry cleaner will indeed speed up your PC, making it boot more quickly and run faster. Far too often, program updates and installers leave unneeded pointers in the registry, so the registry becomes bloated with unnecessary entries, slowing down your system.

Compounding this problem is the fact that applications are usually too inept to uninstall all of the registry entries they create.

Win7 registry repair