vista activation problem

[Qlen]

I bought a copy of vista ultimate from ocuk a few months ago and have been using it since. Unfortunately i had a harddisk failure and had to reinstall everything including vista. However upon attempting to activate it tells me the Key is already in use and i need to buy a new one...
Question is, what will happen if it doesnt get activated and secondly is there a way i can get it to activate properly once again without having to shell out another 120 on somthing that should already by working?

thanks

 

[Qlen]

yeah i just did it over the phone and it worked but im still wondering why it wasnt able to do it over the internet :/

thanks for replies guys