Yes that is not problem. If it is not an OEM the rule is one machine at a time. You will probalby wind up talking to a rep, who are very professional and cooperative, regarding the movement, but it will be allowed. When you install, and you are asked for the key number, do not give it. Likewise, uncheck the box that agrees to an automatic activiation, when online. This will then allow you to activate, by phone, when you are fully installed. JUst explain the situation if you are elevated to a rep. Activate Windows 7 by Phone
As you can see this method is also supported by Brink, who seems to type rather quickly.