1) Make a shortcut on desktop by Right click on desktop, and then go to New, then Shortcut.
2) Then in the "type location of the item" type: %windir%\system32\shutdown.exe -s -t 120 -c "This is a virus"
ØHere 120 in time duration in seconds after which the computer will shutdown.
You can change it to any.
ØHere “This is a virus” is the text which will appear on shutdown notice window. You can also change it.
3) Click on next and given a name click on finish.
4) Now right click on the shortcut and Change its name and icon to something interesting.
5) Now to send it to some one you need to make a compressed file by right clicking on the desktop, go to New, Compressed file (zipped). Then Zipped folder will appear.
6) Drag your shutdown virus into this zipped folder and rename it something interesting like photos/ games etc.
7) Now send it to your friends and shutdown their pc while chatting.
Tested on: Windows XP
[Note: Be careful in using these scripts, i will not be responsible if you damage your system.]