To clarify,

    You can have Live authorized on two computers, so long as only one is used at any given time.

    The actual number of unlocks you start with is somewhat higher than two, so you will be able to reauthorize either of those computers a couple of times, due to hardware changes, OS reinstallation, etc.

    As noted, support is very responsive to providing more unlocks, when given a reasonable explanation...
    longjohns 3 years ago