Can I transfer windows activation?

I am going to buy a new harddrive for my desktop, and I was wondering if I can activate windows on the new harddrive. I bougth Win XP Pro Like a month ago and its already activated.

 

Yes, you can most certainly activate your copy of Windows XP on another drive. Microsoft uses an algorithm to determine if you are installing it on a new computer (hard drive S/N, processor S/N, etc). Just swapping the hard drive shouldn't trigger the "new computer response". Even if it does, you get one free install on a new computer. After that, you can still install on a new computer, but you will have to do it over the phone with Microsoft. I did it one time because I kept getting copies of XP pro, so my XP home kept migrating to older computers. Basically, the girl on the line asked me if that copy of XP home was installed on any other computers. I said no, and she activated it.

In other words, as long as you have the cd-key, you are allowed to install your copy on different hard drives, or even different computers, as long as it is only one one computer at a time. Though you might find it easier to just ghost your existing install onto the other harddrive. I know Seagate drives come with a utility to do that.