Dell L800r – Com Port Problem

I suspect that com ports must have gone changes that I am unaware of. I am currently attempting to connect a bar-code scanner to com 1 of the above computer. I have tried from DOS and a DOS window beneath Windows 98. Only one time has the device ever been recognized and only when the machine was booted to DOS. All of my other experiments and tests to determine the problem have led nowhere. I have tried this on two different machines that are configured the same so I don’t believe it’s a hardware failure. If anyone has beat this problem, I would appreciate your input. Thanks!