Activate office pro 2010

[Fredsone]

Hi
We recently HAD to reinstall/reset this computer and now cant get the Office registration key/code to work.


In short, we started experiencing blue screens and other significant problems and then lost the ability to access the internet. It was decided to reset (or what ever it is called) the computer to its original delivery configuration and then reload everything that we added after we purchased the computer.

All went well, we didn't experience any problems with the reload and product keys/codes worked well (even Vista didn't complain when it was upgraded to Ultimate) .
Unfortunately when it was time to load office we encountered a problem, we are being told that the product code we originally used to install Office is invalid.

The version of Office is;
Office Professional Plus 2010, as in this instance, we originally loaded the office suite from the internet and entered our code when prompted during the instillation process.

I have checked the trail download we are currently using and it is what we originally had. I.e. "Microsoft Office Professional Plus 2010" at 889MB.
Also, we still have the originally installed Office Pro 2010 (along with the rest of the system) in a file called "Windows Old".

So what to do,
Any Ideas re the failed product code?
And is it possible/easier to use the Windows Old files to reinstall Office?