Vista - driver problem for Logitech trackball

After making some changes in my computer, installing a new fax modem and
updating my Internet Security software (Trend Micro), I started to get
messages about needing to find a driver for the Logitech Trackman Wheel I
have been using each time I booted up, even though the mouse (trackball)
was working OK. When I tried to locate a driver, Windows couldn't locate
one. I tried to tell this window to not ask me again, but it then disabled
the mouse and made it inoperable. It took quite a while to get it working
again, including uninstalling and reinstalling the Logitech Setpoint
software, but I still get that message every time I boot up. I spent a LOT
of time on the phone with Logitech, and they tried to be helpful, but
eventually told me it had to be a system problem, and to contact Microsoft.
One rep there did suggest running System File Checker, but I got the same
message that I saw discussed in the maintenance and performance section, that
there are corrupted files that could not be repaired. According to one rep
at Logitech, it looks like I am missing some files in Windows/System32, one
of which was input.inf. Nothing I have done seems to get those files fixed,
or stops the message about needing to find a driver. Any suggestions about
this would be appreciated.
--
Larry S