I have the same problem with my Windows 7 PC and a Logitech trackball. This seemed to start with the most recent Windows updates for Window 7. I doubt that Microsoft gives a crap about our problem. I wish I had bought a Mac
Windows 7 has no recent system update regarding a logitech trackball mouse. Check the logitech website for an appropriate driver for the unit. If possible, click on the picture of the mouse. Maybe pray a little you find your way.
If the trackball itself works, then power down your system. Disconnect the trackball. Start Windows back up. Allow it to boot fully without the trackball attached. Once fully up, and assuming your trackball is USB, reconnect the trackball to an available USB port. This should force Win 7 to reload the drivers. Good luck!
there has been only 2 updates for my system since the beginning of march if you have already upgraded to sp1.
go into control panel/ programs and features/view updates and sort by date. you should see the latest 1s dated 9th of march or there abouts, un-instal them reboot and see if it fixes the problem. its unlikely that the m.s update is responsible, but worth a try.
NOTE: neither are for logitech devices
if that doesn't fix it. then reinstall em, reboot and remove the device and un-install its driver.
now install the latest driver for the device from logitech, 1s its installed plug it back in and the install will finish and the device should then work.
the chances are its something else in the usb hub conflicting or it may be that your usb hub has run out of bandwidth.