Win 7 Office 2007 not accepting keyboard entry

[sixto]

In the wifey's Dell XPS running Windows 7 and Office 2007, MS Office programs won't accept keyboard entry. Not text, not keyboard shortcuts, not functions keys, not pasting from clipboard, not inserting images... Most program functions are grayed out. I tried the advice here -

Office 2007 - keyboard won't allow typing letters in Word or Excel - Microsoft Community

but it's set to US English exclusively (we're in the US, laptop was delivered new in the US). PC has been restarted numerous times. Avast says the system is clean. Other programs accept keyboard entry.

Anything else to try besides getting a Mac?

Thanks,
Sixto