As for CCleaner 5.46, if you can get past the initial frustration of the auto-update (provided you installed a version between 5.34 and 5.45) it does work a treat. I'm actually back on 2.36, an ancient version that will even work on 98SE and (if I'm not mistaken) NT 4.0. It's just as good at clearing out junk files and keeping the registry clean as newer versions (at least for the programs I regularly use), while coming in a much smaller size (the install .exe is only 1.13MB) and requiring a lot less RAM as well as processor power (I've successfully used it under 98SE on my IBM Thinkpad 380ED with only 48MB of RAM and a 166MHz Pentium MMX processor--not as fast as CCleaner 1.41 under 95 OSR2.5 on the same hardware, but it works very well).