Hi Sweens,
Should not really be a problem..On the activation tab on the desktop,
go to the activate by phone option, select your country, and telephone
microsoft on that number..I am sure if you explain what happened, they
will help you. Good luck:)

fly

Something has invalidated your existing activation. If you can't activate
automatically over the Internet, you need to ring Microsoft and get an
activation code. The error message you saw should have given you the phone
number for your region (it varies, according to country). It's pretty
straightforward, you just ring the number, ask the support person for a new
activation code, and they give it to you, then you plug it in to Windows -
should only take about 3 minutes.

The algorithm to detect "hardware changes" is pretty complex and not public,
so it can be hard to say what will provoke a re-activation. If it isn't a
genuine hardware change (keyboard? I dunno) it may be a virus, which
deliberatly deletes your activation information. So make sure your
anti-virus signatures are up to date and run a full scan of your system.

Hope this helps a bit,
Andrew