Shut down, move it to a different USB port, and reboot.
If that doesn't work, go do Device Manager and uninstall the driver, then refresh the Device Manager to reinstall it (on Weven, "Scan for Changes").
If that doesn't work, run a disc scan, to look for/repair bad sectors.
If it's still no good, then look for any software that you installed when you first got the device (if anything), and:
- Check each executable and DLL in its installation directory for dependencies (Dependency Walker is good for this), making a note of any that are outside of the device's proprietary directory (e.g. in the Windows dir/system dir/shared dirs).
- Uninstall the software, making sure that the proprietary directory it was installed to is really gone (i.e. delete it manually, if it's still there).
- Check any of the dependencies to files in other directories. If the files were made by the company that made the device. rename them (as long as the device wasn't made by Microsoft).
- You can get rid of any registry entries, too, if you do that kind of thing (if you've never edited a Win registry, leave it).
If that doesn't fix it, you'll probably have to settle for getting some new hardware.
I wanna be a eunuchs developer! Pass me a bread knife!