Mike Mullins has written a great post over in the TechRepublic IT Security blog that captures a lot of my feelings about registry cleaning programs, and I think it's worth drawing attention to here for readers of the Help Desk blog.
A few weeks ago, I wrote a post listing some of my favorite utilities for Windows maintenance. Many readers mentioned in their comments other programs that they've found useful, and a lot of these were registry cleaners. I kept mum at the time, but I have to admit that I don't use these types of programs very often, and I wouldn't recommend them to anyone but the most advanced users.
The Windows registry is flawed, that's true. When it comes to the Windows installations I manage, I'd rather re-image a machine and start fresh with a clean registry than try bandaging any problems. Also, registry maintenance programs can cause more harm than good when used by someone who doesn't have a full understanding of what's going on under the hood. I find for most users it's usually better to let Windows take care of itself when it comes to system tasks: uninstalling programs, maintaining the registry, or managing virtual memory. Microsoft's engineers know better than anyone the arcane underpinnings of Windows' system routines, and their built-in handlers usually get the job done well enough.
Employing registry cleaners to shave a few milliseconds off of system boot times or to chase improved efficiency smacks of "tuner" behavior to me. If you want to be a tuner, then more power to you, but be aware that those types of car guys sometimes burn their engines out.
I'm sure I'm going to hear from several help desk pros who have used registry cleaners to solve pernicious Windows problems and are ready to sing their praises. Good on you guys. But I'd bet that—to a (wo)man—you're extremely experienced Windows users and admins who didn't undertake your registry editing lightly. That's because registry cleaners are specialized tools that, unless drafted for a very specific purpose, are better left alone by the average user.
If users get to the point where they might need a registry cleaner, that's when they're supposed to call us.