Error Starting PC-VCR

How can I determine what program or software Windows 2000 "thinks" is
using
the video hardware?

I'm currently using a Marvel G450-eTV on Windows 2000 with the latest
Driver
and Video Tools. Normal display operation seems fine, but when I
start the
PC-VCR application, I receive an error "Matrox video editing hardware
is
currently not available. . .", followed by suggestions to close any
program
currently using the video hardware. I'm not running any other
software that
I'm aware of, and have shut down all my regular background programs.

An important note - I used to have an ATI card (not currently
installed) earlyer on in the system may be there are some thing left
in the windows configuration to deinsatll.

Thanks for your Help

Alex