I took this to the IT guys at work and they got it to work. It really doesn't matter what operating or computer system you have!!!! You have a block on your com port. I had Palm pilot software loaded that was locked into it and I didn't know it!! Even though I didn't have the cord in it locks during startup each time. Close the program and remove the from startup. If you have 2000 you can go into the control panel, services and double click com & events and hit stop! Works great now!