[Cory5412]

You don't have to prove anything to them, you just fill out the form and get the CDRom.

Even better, you don't have to reinstall anything if and when you buy a license from them, all you will do is click an activate button and enter in your new serial number. The trial disc is literally the same as a full version disc, except that they tell you to use the serial number 000-000(some number of zeroes)