The simple fact is that at least 99% of registry errors are completely harmless and there will absolutely no benefit gained from removing them - making it pointless to do so. Also, 99% of registry cleaners have trouble identifying errors, and will list some valid registry keys as errors. Deleting those keys can cause problems. The actual registry "errors" found, can be safely deleted - but once again there is no need to. CCleaner and Glary Utilities are two examples of software with registry cleaners which are unsafe to use. It is very rare indeed to increase PC performance or reduce error messages and crashes by cleaning the registry. Over time the Windows registry will accumulate a lot of errors, particularly so if you install and uninstall a lot of software like I do. But all the junk accumulated in the registry really does not matter.