Because I can't test every possible application out there, I decided to test the 8 most well-known ones. As I said on the main page, I tested all these applications using a virtual machine which allowed me to test all applications on the exact same setup (so I could compare the errors found in absolute terms). If you're interested in testing the applications themselves, you can download Microsoft Virtual PC 2007 for free here.

Top 8 registry repair tool comparison
Application		Free Scan	Easy to use?	Summary	Overall Rating	Link
1	[Registry Fix]			Top score. This application fixed the most errors, reduced the registry size the most and increased PC speed by at least 20%	10.0
2	[ErrorFix]			Very good application. Not much difference between this and Registry Fix, caught practically as many errors but took a bit longer.	9.8
3	[Registry Defense]			Caught slightly less errors than the previous two but was faster than Error Fix.	9.0
4	[Registry Sweep]			Picked up on 86% of the errors Registry Fix picked up on. Was quite slow but improvements were apparent.	8.6
5	[Error Smart]			Slightly less easy to use than the others due to weird lay-out within the application. Once started, it was fast and detected 81%.	8.1
6	[WindoFix]			Found around 80% of the errors. Easy to use to fix the problems after the scan.	8.0
7	[Registry Easy]			Relatively long scan time but found most of the errors. Lay-out of the application was easy enough, no problems there.	7.7
8	[Registry Smart]			Worked easy enough but found the least number of errors, 75% of the errors found by Registry Fix. Scan time was quite fast.	7.5