I had an Office Standard 2010 installation which did not fully un-install at the first attempt. It's still in the list of installed programs, but some of the files and registry records might already be gone.
When I try to uninstall it, I now get the following error:
The language of this installation package is not supported by your system
I have already tried the suggestion at the How to uninstall or remove Microsoft Office 2010 suites article at Microsoft Support.
How can I get rid of that nuisance? In order to install a 64-bit Version I have to uninstall this one first.
Use the "Fix It" for Office 2010 provided by Microsoft here: http://support.microsoft.com/kb/971179
It'll take a while to run and won't provide much feedback during the process, but it should (might) remove all remnants of Office 2010. Be sure to reboot afterwards.
You could also try manually removing it following the instructions here: http://support.microsoft.com/kb/290301.