I’m using this for XP.
1) Go to Start menu->All programs->Accessories->System Tools->Scheduled Tasks
Just Run “tasks”.
2) Add scheduled task:
Browse and select the program:
C:\WINDOWS\system32\shutdown.exe -s -t 60
Select how often and what day(s) and time you want to run this program, enter username and password of your window user.
Before “finish”, check “Open advanced properties for this task when I click Finish, in “Run:”, you should see “C:\WINDOWS\system32\shutdown.exe”, add “-s -t xx” at the end. xx means how many seconds before it shuts down.
e.g. you’ll have “C:\WINDOWS\system32\shutdown.exe -s -t 60”.
If you want to something else rather than directly shutdown, check “shutdown/?” in command prompt.