If you are into coding, then just look into C# or Visual Basic codes provided, whichever you like, to see what goes into this prank and how it was created.
Else if you just want to have the prank, just goto the deployment section to read , how to deploy it on somebody's PC.
How to deploy:
"Simply copy the AprilFoolsDay.exe and AprilFoolsDay.exe.config files to his or her PC. (You may want to enlist someone as the “lookout” so you don’t get caught while doing so!) Create a shortcut to it in the Startup program group, or set it up to run via the registry using the following key for the logged in user:Thanks to Brian for this.
Simply create a new string key with any Name, and a Data value of the path to the executable.
Next, start the application once on their PC to setup the date and time for the show to begin. Once that is done, the application will remain running in the background. If the PC is restarted, and the application is setup to run at startup as described above, it will start silently and remain running, waiting for the date and time specified.
If you need to reset the configuration for any reason, simply run the application from the command line with the -config switch and it will display the configuration dialog box again."
So have some fun !!