I bought 2 Windows 7 Pro keys from softwareseller. Both activated without issue. From my long history of dealing with keys of this exact nature, I do not expect to have any issues at all. Like I said earlier, the only trouble you will have with these keys is if you try to use them on two machines.

The other issue you MAY have is if you wait too long to use them. MS seems to be willing to deactivate keys if they have not been used, but I have never had them inactivate one of these keys that has only been used on one machine.