Step one: right click on an open area of the desktop and select New, then Shortcut.
Step two: in the text box type "shutdown.exe", without the quotation marks, then click Next.
Step three: Type "Internet Explorer", again without the quotations, then click Finish.
Step four: Right click on your new shortcut, then click Properties.
Step five: click Change Icon, then click Ok.
Step six: find the icon which looks most like the real Internet Explorer icon. Select it, then press Ok
Step seven: In the box labeled "Target" go to the end of the text in the box and add -s -t 30 -c "message of your choosing"
then click Apply. It will look something like %windir%\system32\shutdown.exe -s -t 30 -c "message"
Last step: double click your new shortcut to test it. Oh, by the way, click start, run, type shutdown.exe -a, click ok...these are the steps for aborting before shutdown.