I've had the same experience with Windows activation. Even with a retail copy, which is supposedly more forgiving with activation than an OEM copy, it will want you to phone in after activating it so many times, even on the same machine. Then sporadically, it would successfully activate online again after having to phone in after a few reinstalls. Eventually I just kept track of exactly which drivers I had installed every time I activated it, and wrote down the activation code, which stays the same as long as you try to activate it with the same hardware configuration after each reinstall. That way when it asks you to phone in, you just type in the code that you wrote down on the last install. And then sometimes I would be ready to type in the code, and it would successfully activate online with no explanation of why it suddenly decided to work this time. It's screwy to say the least.