I tried to use the "Scheduled tasks" (if I translate correctly into English) to make the computer run defragmentation, disk clean-up, and various anti-spyware programs at 2 o'clock in the night so that I can start in the morning with a fresh computer. But it doesn't seem to work - the programs just stand waiting for keystrokes in the menues.

Is there a way to make this function well, automatically, while asleep at night?

See if anything here helps:

How To Schedule Tasks in Windows XP
http://support.microsoft.com/default...308569&sd=tech

How to troubleshoot scheduled tasks in Windows XP
http://support.microsoft.com/?kbid=308558