#1 Is there a diagnostic software that can tell you what softwre has or is using what com port? #2 I am getting an error in 15-30 minutes after dialing out on my modem. This is dial up credit card processing software that dials on demand for CC authorization. When I look at my CC program it say that it is unable to open the com port because another program is using it. Use task Manager to close the program. It mentions SmartWin but I can find no reference to smartwin on the computer. There is a Lexmark All-IN-ONE printer #7100 attached via USB port. It has been connected since June last year and the problem started in June of this year. Any ideas would be appreciated. The sun will come and go, weather its hot or cold.

Hi, Sounds like an address or IRQ conflict. Do you have the BIOS SETUP set for "OS is Plug and Pray"? If it's on Windows will take care of IRQs and addresses. Usally the port on the top would be COM1 if there are two and the single would be COM1 if a single. That's on an ATX system. Hope this helps a bit. Good Luck, Jim

Sorry, guess I left out major details, system has com 1 on the MB and I have a PCI Digi Adapter with the ports configured as com 2 & 8. The digi operates modems on both ports and does not have any problems. IRQ's are handled by the PCI card. The sun will come and go, weather its hot or cold.

Hi again NU, The only other thing I can think of is to make sure the PCI board is not set to use IRQ4 on either port. Check in System Manager on all three ports. Addresses are obviously not a problem. Windoze is probably setting COM1 to IRQ4 the standard setting. Win really should be preventing that, but who said Plug and Pray was always right. More luck, Jim