The primary function of CCleaner is to remove temporary files from your computer, & as stated does a very good job. It also has a registry cleaner (aka "Issues") that is fairly safe to use from time to time. CCleaner is recommended to be run frequently: usually after your'e done for the day, before you run any AV/Anti-Spyware scans (to make them run more efficiently) , as well as when you install/unistall programs on your computer.
Edit: Since I saw your 2nd post after I posted, to answer your question, yes it does clean more than just IE. You will find what it cleans within CCleaner, under
Cleaner>Aplications.
I haven't used PC Booster, but it has more functions than CCleaner, & seems to be more of an overall system optimizer including diagnostics/tweaks for the system, desktop, start menu, internet, boot-up/shutdown, etc..
I'm not sure if your'e referring to PC Pitstop's online diagnostics, or their Optimizer program which is similar to PC Booster. The online diagnostics checks your PC for security risks, Windows configuration issues, performance problems, measures disk fragmentation, checks available system resources, analyzes device drivers, benchmarks the CPU, memory, video, disk, and Internet connection, looks for viruses and spyware in running software, and checks for common security problems.
It does not change anything on your system at all. What it does do is present you with results that include the current status/configuration of your system & makes recommendations as to what you can do to make improvements to your computer.
This post has been edited by hillbillygreek: 09 December 2006 - 01:14 AM