They originate from Microsoft software swap keys obtained through authorized resale platforms.
They originate from Microsoft software swap keys obtained through authorized resale platforms.
They might come from MSDN or similar sites, but they usually lose validity after a year.
Currently they're valid identifiers, though it's hard to confirm because many haven't been used long enough for MSDN access to lapse.
Learned you can purchase used keys after obtaining your official one, even though it was installed via USB for four times the cost.