Right now I have a friend staying with us, and he’s using my computers for various normal tasks.
He’s not a techy kinda guy. However, without instruction, he figured out User switching without difficulty.
That is why I still recommend Macs to people. The hardware is OK, still too expensive, but you have to admit they are easier to use.
Instructions in Windows XP:
Step 1: Press Windows Key + L
Step 2: Select other User
For more info: http://support.microsoft.com/kb/279765