I have a account on Microsoft volume licensing service center but can not do a product activation on a windows 8.1 computer with Microsoft Office 2010 already installed on it.

Hi,

It's hard to tell how to resolve the issue based on the provided information. More details about the scenario are preferred:

1. What type of Volume Licensing are you using? MAK or KMS?

2. Can other Office be activated fine?

3. Have you got any error message when you can't do the activation?

Regards,

Melon Chen
TechNet Community Su