Sounds like you may have a problem with ghost drivers...Remove all modems in Device Manager then boot into safe mode and make sure the drivers are in fact removed...try deleting these files also:
C:\windows\inf\drvdata.bin
C:\windows\inf\drvidx.bin
C:\windows\inf\other\===everything in this directory
these files may be hidden so make sure to "show hidden files" or you can just delete them from DOS. This will force windows to rebuild it hardware database and allow you to install the .INF files off the cd. Most modems do okay on COM3 as long as you DONT have a serial mouse or any other device plugged into your serial port. I think if you go into safemode you will see drivers "still" installed for another modem which Windows thinks is using your other COMport. Hope this helps.
