Help with HotSync

I am trying to get a new to me PDA to Hotsync with my Dell PC with not much luck. Everytime I try to connect the PDA to the desktop, I get an error stating that the Port is in use by another application. The Sony Support people were not overly helpful. I was wondering if anyone could tell me how I can find out which application is interfereing with the port. I am using the USB port on the front of the PC. The only other software that I can think of that could be causing a problem would be something that installed with my digital camera. I cannot seem to find that program though. Any help would be appreciated. Mux