Unattended activation of retail XP(inc SP2)

[baliktad]

For some license types, Microsoft disallows internet activation completely. They publically admitted to doing this early last year. This affects you if you have an OEM machine and you're using the key from the sticker on the side of the box. You'll just have to call every time, as internet activation is simply not available. However, if you do have an OEM machine, use the oembios.* files and the SLP key your OEM used - this also disables activation on machines from that manufacturer.

I also suspect, but cannot confirm, that Microsoft has the capability to flag suspect keys as "potentially shared" if you attempt to activate too many times via the internet. If you cross that threshold, they will only allow phone activations for that key - to prevent against those people who share retail keys amongst friends or multiple computers without realizing this is not allowed. Again, this is all speculation and I have no confirmed proof this is the case, but it's why I advocate method #1 below - only activate when absolutely necessary!