Bluetooth Trouble, need help

So, I've bought this bluetooth adaptor for my PC, so that I can use my PC to awnser calls while my phone has access to good reception... but I have a problem.

Phone- HTC Desire
PC is running Win 7 Home Premium 64bit
The BT adaptor is USB

No matter which way I attempt to pair the phone and PC the pairing never completes, meaning I can't connect the phone to my PC. The phone pairs without problem to my brothers laptop,

I really hope I can get a definate awnser, Thanks.