I suffered with an occasional comm port error whenever I restarted my computer and attempted to restart Weather Display for a many months. I couldn't figure out what was wrong. I would have to keep restarting my computer to get Weather Display to start. Well I finally figured out what was causing the error and no longer get the occasional comm port error so I thought I would share this in case anyone else is having the same trouble. The issue effects Windows XP and Oregon Scientific 968 weather station, maybe other brand stations too. When the console is connected to the serial port on the computer, Windows XP automatically installs a driver for a serial mouse. The driver is for a Microsoft ballpoint serial mouse. The next time you restart computer and get the comm port error while trying to run Weather Display, this is what you do. Go to the device manager, (start, control panel, system, hardware and click on device manager). Under (mice and other pointing devices), you will see Microsoft ballpoint serial mouse and your PS/2 compatible mouse. Right click on Microsoft ballpoint serial mouse and select disable. Close all windows, restart your computer and occasional com port error is fixed! Hope this helps someone.
Billy
Had this happen to me today for the first time. Have to give you a sunny 
for making me aware of this problem. What happened to me was I had a tab on my task bar that I couldn’t get rid, something about ftp and IE. I went to the task manager and killed the process but it took my desktop manager with it and now I don’t know what programs are running. So I decide to reboot my machine and while it’s booting up it said it had found new hardware! I’m thinking to myself, “What new hardware?”, and then I see it, the ballpoint serial mouse.
No problem I think to myself, I read about this on the WD forum. So I wait until XP finishes loading so I can remove it, wrong! My mouse is so jacked up I can’t get it on anything to click, it’s faster than I am!! It’s been years since I tried to navigate with no mouse, but I managed to get into the control panel, checked my mouse settings, and there it was, the dreaded ballpoint device. I disabled it and life is good again. Geesh!
Thanks again Billy.