I think the licence is for two computers only. MS W7 is for one only, Office suite 2007 for 3, etc. If you could buy one DVD and simply copy it for as many PC's as you like, the vendors would soon make no money. You can de- register it from one PC and put it on another PC.
Two machines only I'm afraid. Version 8 actually has to be activated, but this is done in the background without any message that it is so doing. You do not see it happening. If you install to any more than two machines you will get a message that you have exceeded your licence. If you look in Help\About you will see an option to de-activate so it can bee installed elsewhere, but no more than two at a time. One of these must be on a portable as well.
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