Windows XP comes with its own shortcut utility, shutdown.exe
Click on any empty space on the desktop and click on 'New Shortcut'
For Shutdown enter the below code shutdown.exe -s -t 0
For Restart enter the below code shutdown.exe -r -t 0
For Log Off enter the below code shutdown.exe -I -t 0
Now click on next and give a name to your shortcut. Then click on Finish.
Note the -t switch, this stands for time. -t 0 means the shutdown or reboot action will begin immediately without delay after clicking your shortcut. If you wanted to hold off the shutdown and restart for a certain length of time, for whatever reason, then just indicate the number of seconds after the -t. i.e. -t 30 would wait 30 seconds before shutting down or restarting.