Where can I check to see if my Microsoft Office disc is still good for another install?

You can look it up in your EULA (end user license agreement). It just depends on which version you have. If it's the home and student version, you have 3 licenses (meaning 3 different computers can run it).

Here's the EULA link

http://www.microsoft.com/en-us/legal/intellectualp...

I'm trying to educate you! Why are you bothering with M$ office when you can have the latest August 29th 2013, Linux Libre office package for FREE. It has all the same features that M$ office 2010/13 and 365 has and more besides,

You need to understand that there is no need to buy any software to day there are over 43,600 free professional application software packages available There is a 100 other Free computer operating system that are superior faster and secure and are far more advanced check out these web links,

Free Linux Office suite (for windows) released today, 29th August 13

http://libreoffice.org/

http://openoffice.org/

Top 100 Free Linux operating systems

http://distrowatch.com/

43,600 Free professional application software packages

http://sourceforge.net/