While there is a limit to the number of copies you can run, if some are no lorger being used, you can still load on a new machine, up to your maximum. Also, you can buy a legal copy of Office 2007 on the Internet that can be activated.

I really did not like Office 2007 and waited till Office 2010 to start using a Ribbon version, but Office 365 will take a bit of relearning, Basically, if you just think of the File Button as the Office Button, you should be OK.

The Ribbons of Microsoft Word 2007-2013