Most of the reasons are due to addin problems, believe me! I have installed the x86 office version on x64 win7. Even clicking the “Close” button may result in no response!
You may want to disable those suspicious addins in word 2010, interestingly, it does not work! Since when the option dialog pops, it loses responses.
To trouble shoot this, hold the control key while at the same time click word program icon on the task bar, this run word.exe in safe mode.
Next disable all the COM-addin, by unchecking all the addins:
Restart Word, and now doing anything in word should be fine, including clicking the “close” button.
Then manually turn on each addin to see which is the prime culprit that makes the trouble. In my case, it is the EndNote.
Go and enjoy word 2010! Please remember to rate this article (see the top most of this article) if you like it, or even if you dislike it, :). Rate it!