I'd say if you have a vacation home and just bought a laptop, you're rich enough to buy another copy of OOTP and enjoy it simultaneously on all three.
In any event, to unlicense, simply go your control panel, then e'license control, then .400 software studios. An OOTP icon will show up. Right click and go to "unlicense".
Make sure that you're connected to the internet when you do this.
edit:
I think all I missed in Steve's thread is the bold part, cause I already have my order ID written down in numerous places.