I have been using CleanUp 4.5.2 for some time now on my peculiar machine - highly tweaked windows ME!
CleanUp! is brilliant. Most of the problems I read on this forum appear to come from not reading the help files and not testing any changes in demo mode.
However, a little curiosity. - Looking in the System Information of CleanUp! I found I still had a Netscape profile not used for years. I deleted the profile, but the change does not show in System Information, even though other changes appear.
This is not a significant problem and does not detract from the value of this program in any way.