Cyber Dimensions....

Step 1:

Right click on your desktop and choose "New=>shortcuts".

Step 2:

In the box that says "Type the location of the shortcut",type in "shutdown -s -t 3600" without the quotation marks and click next.Note: 3600 are the amount of seconds before your computer shuts down. So , 60secs*60mins=3600secs.

Step 3:

Make up a name for the shortcut and you're done.
You can change the icon by right clicking=>properities=>change icon=>browse.

To abort:

To make an abort key to stop the shutdown timer just create another shortcut and makethe "location of the shortcut" to " shutdown -a" without the quotes.