Hi. The following message appears whenever I start Office 2010: 'Product Activation Failed'
Can I purchase a product code online or do I have to install another version?
The Plus version is normally a Volume Licensing version, used by corporates etc. This verion is also very often 'cracked' or stolen.
Which one is your?
Install another version. I doubt you have a proper licence for that version of office, unless you got it from a MAPS pack or something similar, which is the cheapest way to get it legally.
I had exactly the same issue on my wife's retail 2010 Office - it kept deactivating after a few months. I got tired of calling MS every few months to have it "fixed", so I cracked it... not ideal, but how many times must I call to have it activated, particularly since I paid for it in full!