Wait! I got it!
Go to your local Best Buy and go over to any of the Compaq's for sale. Call your house and record the Win XP key on your voice mail.
Take that key and a rip of your XP disk to an optometrist. Trade the key for a prescription that requires you to tint your front window beyond the legal limit.
Now, here's the kicker....
Let this person that is annoying you drive your car around da' hood. Tell him that if he finds some dope, to buy it and you'll pay him back (and slip a counterfeit twomp in his wallet).
He'll certainly either get pulled over for the tint and arrested and then date ***** to death in prison, get shot in da' hood for fronting wacky paper, or maybe even get tracked down by the actual owner if the XP key that you blatantly ripped off, and get beat to death with a trout.
Looks like a win-win situation to me.