What type of scanner is it. If a parallel port type using passthrough connector (yuk) these inherently have problems. If it is, go to manufacturers site they may have a work around for you, or even the printers, I know HP do. If it is it is recommended fitting another parallel port, £10. Sorts most problems. uninstalling drivers may not always work. It may also be worth deleting it from your windows device manager, and maybe also the parallel port, let windows install the port drivers before reinstalling the scanner.
Good luck, best thing is to use a USB scanner if you have the ports etc.