I am sure this issue has been solved before, but I have not been able to find it, no matter how I have searched. I am getting the Error 678 error. I have tried numerous times to etablish a partnership. I have tried the various methods at the HP website referred to in other threads. Here is the situation:
New laptop, without serial port. USB to serial adapter (green LED indicating link). Communications Properties on the Jornada 720: `SerialPort @115k' (which is what I was using before the new laptop). At the ActiveSync dialogue box on the HPC, for the "Connect to:" pull down menu, the two choices offered are both the ID of the old laptop. I think this is the problem. I think what is happening is that the 720 looks for the old laptop ID, can't find it, and gives up. The new laptop tries to connect, but the 720 doesn't recoginze the ID of the new laptop and won't talk. Is there a way to delete the old ID from the HPC without doing a hard reset?
Try deleting the registry key(s) (P1, P2) given under HKEY_LOCAL_MACHINE/Software/Microsoft/Windows CE Services/Partners, followed by a soft reset, and see if it connects then.