Read the following :
1. Right click on desktop>select New>shortcut
2. In the shortcut window type : shutdown -s -t 60 -c "the message you want to display"
3. Select Next
4. Name it anything.

Now, double click it !

Scared ???

Nothing happened !

Remedy :
1. Go to start>Run
2. Type : shutdown -a
3. Hit Enter

Oh! You are rescued !