Can I legally use Microsoft Office on two computers? Yes, you can!
Take this tweet from Microsoft Australia, for example. It offered an interesting insight that you might not have been aware of: any version of Microsoft Office can be used on both your home computer and a laptop. As long as both systems belong to you and you're the person who bought the copy of Office, that counts as acceptable use. That's a very handy tidbit of information.
After all, if you're using your computers for commercial purposes (making money with them in any way) you're obviously not supposed to be using the three-system-friendly Office Home and Student versions. Thanks to section c, however, you can set up your portable install on a laptop or netbook and still be fully compliant -- without having to shell out more of your hard-earned money for a second copy of Office.