Windows Installer keeps trying to install Office 2007

I had the test version of 2007 and decided I didn't want it, but can't seem to delete it, as the file 'GrooveMisc.dll' can't be deleted. The most annoying result of this is the random appearance of Windows Installer trying to reinstall Office 2007. Is there any way to stop this short of reformatting my machine??

I followed (or thought I did) the very lengthy manual installation of Office 2007 found at Microsoft. It took well over an hour to delete a whole bunch of registry keys. Most of '07 seems to be gone, but something keeps triggering the Windows Installer. Any ideas??