I use System Mechanic bi iolo @ www.iolo.com . It works great for me - cleans the registry, deletes abandoned shortcuts, deletes temporary files, allows you quick access to startup items (registry based or start-menu), lets you customize some windows options, remove invalid uninstaller information, privacy options for internet and email, optimize internet and network speed, and securely delete files and folders. I won a copy of the industrial version years ago by entering a contest and get free updates for life. It's truly a decent piece of software.
Oh, I only had a problem with it once - I gave in to Windows ME when it was initially released, used the reg. cleaner portion of the program, and had instant grief. I had the option of reverting back (the program does make a backup of any registry changes) but decided to get ME off my computer instead. I gave my paid for copy of Windows ME away and never looked back. I have used it on Windows 98, Windows 2000, and WindowsXP Professional. I've tried other programs and combinations of programs but haven't found anything so reliable.
