What are you doing that makes the message come up? Is this every time you open a Word document?

This is the MS Genuine Validation software. It is NOT saying that your software is invalid. This is usually triggered when you want to download a program or add-in that wants to check to see if you are running a valid copy of Windows.

All this message is telling you is that it can't run the check. It can run in Internet Explorer as a ActiveX control - or in another browser as a program file that you download and run. (That's what the "Validate Now" button does.)

However you do not have to validate anything to continue to run Office. Only if you want to download and run whatever new software you are trying to get.