Start/run, type "msconfig". Uncheck everything there except essentials like antivirus...then reboot.
The essentials in task manager are explorer.exe and svchost.exe. Not sure about the rest. But I shut down anything that i recognize as a program i have. If there are memory intensive programs running there, google search them and that will tell you what they are. I dont worry about the little ones running.
Also he will probably want to run an antivirus check, spyware check and ad-aware check. All these programs are free. Search these forums for more info.