The best registry repair tool is the application that's able to scan through your computer and get rid of the largest number of possible issues that it may have inside. The problem for Windows XP is that this version of Windows is over 10 years old, and will likely have a large number of older settings & options which will prevent it from being able to run correctly. If you're looking to use a registry cleaner to fix any of the errors / problems that XP may have - you have to be able to use a program that's going to be able to cure the various issues this system will have, in the most effective.
Although there are a large number of registry repair tools which claim to be able to work well on XP, the fact is that most of the programs that are available out there have only been created to work on the later versions of Windows, and will likely cause problems for any versions of XP that you use it on. It's vital that you get a registry cleaner program that's able to fix the largest number of problems because these programs have been specifically created to get rid of issues inside the "Registry Database" of Windows - a centralized database that allows your PC to keep the likes of your most recent emails, desktop wallpaper and passwords safe.
Despite the registry playing an important role in the operation of all versions of Windows, it's constantly causing errors - making it vital you use a registry cleaner to fix the problems that it may have. The best registry cleaner program is simply the tool that's capable to get rid of the largest number of potential issues that Windows XP may have inside, and a lot of programs out there will actually end up deleting a lot of the settings XP uses because they will not recognize a lot of the older settings inside.
The best XP registry repair program is the tool that's basically able to get rid of all the parts of the system that are making it run less reliably - which is best done with a tool called Frontline Registry Cleaner . We've found that Frontline Reg Cleaner 2.0 is an extremely reliable program, which works just as well on XP as it does on Vista & Windows 7.