Problem activating Lync 2010 client

I am running Windows 7 (64) and have installed MS Office Pro Plus (HUP).  Then my company switched from Communicator to Lync and I installed the Lync 2010 demo version.  When the trial use expired, I obtained a HUP activation key for Lync 2010 client, but am unable to enter it.  Whenever Lync is activated, I get the error:

Microsoft Lync 2010 cannot start. The product license may be expired because you are using a pre-release or evaluation copy of the program, or the product key information may have been modified in your Windows registry.  Please uninstall and then reinstall Lync.

I have uninstalled and reinstalled Lync 2010 client several times as well as uninstalling and reinstalling both  MS Office Pro Plus and Lync together.  Also I have received an email from the HUP support (ESD support) that only the 32 bit version is supported by HUP and it should work on both 32 and 64 bit versions (X17-30021),  but of course when I try to run the .exe, I get the error message:

This installer is not supported on your computer. Please use the 64-bit installer to complete the Microsoft Lync 2010 installation. 

A final note the product key that I was sent for the Lync 2010 client activation by ESD support is the same as my Office Pro Plus 2010 activation key, and the office products are all activated correctly, but the Lync 2010 client does not recognize the activation.