The Windows Registry holds thousands of settings—some for Windows itself, some for applications. Over time, the Registry gets loaded down with useless or erroneous entries left by incomplete uninstall routines, application errors, and even misapplied tweaks. Problems also arise when users move files without realizing that dozens of Registry entries point to the old location. We tested six utilities designed to fix Registry problems and clean out useless entries, giving each tool a chance to work on the same gunked-up Windows Xp Registry.
These Registry cleaners made a combined total of over 3,000 distinct fixes. Three or more agreed on about 500 of those fixes. There wasn't a single fix all six agreed on, and nearly half the total fixes were unique to a single application and were ignored by the other five.
All six products let you undo an entire session of fixes; the better ones offer per-item undo. Some even let you specify entries to be excluded from future scans.
