It could be the parallel port gone bad. If so, buy one of those little cards that has LPT/COM/FDD/HDD support on it, turn off the LPT1 in the CPU BIOS, re-configure the little card to be the LPT1. Plug the dongle in and if it works, fine. If it still doesn't work, the little cube that plugs into the dongle will need replacing or re-programming or the dongle itself will need replacing.