I agree. The beta keys eventually expire. Did you try Temporarily downloading the firewall? It may require that is installed on a Windows Enterprise System or Windows Pro Operating System.
In the future:
Short of it being a Work at Home version (Microsoft's Home Use Program) a retail version, (from a store), or an OEM version (pre-installed on a laptop), it may be set up for KMS activation (a complicated thing you don't want to deal with).
In short: Ask your HR department if they have the Microsoft Home Use Program (tell them that you would like a copy of Office 2010 for work purposes if that is what it for (or whatever version they are using on workstation PC's). Many large organizations do that have a volume licensing agreement. You have to pay $9.95 for the disc *(buy the backup disc! It will save you many headaches! Also print out your Product key and put it in several places.)*, but if they offer it it is worth it. Don't think of unauthorized copying of company software, not only will it fail activation, it's illegal).
Alternatively, you could go here and enter your work email to see if you are eligible: http://www.microsofthup.com/hupus/home.aspx
Let me know either way.