Push Ctrl+Shift+Escape to bring up the process list.
I have 24 processes listed at the moment -- 10 which are hardware support or anti-virus, 13 windows internal processes and services, and my Web browser.
If there are more than 30 with no programs open, he's installed a lot of $hit -- if there's loads of stuff running in the bottom right-hand corner (system tray) then this is the likely culprit, CCleaner won't get rid of these as they aren't problems in themselves. If there are programs he doesn't use which always run (those listed in MSConfig) then uninstall them from Control Panel -> Add/Remove Programs.