I've been working on a microcontroller project that routinely dumps status and debug information out its serial port. It always does this, regardless of whether or not anything is listening or even connected to the port.

If I boot my PC while it's connected to this thing, Windows XP often interprets the status and debug messages as mousespeak, installs a serial mouse driver, and then tries to interpret subsequent messages as if they were coming from a mouse. This results in occasional wild cursor movements and random mouse click events on the PC, as though some spastic ghost was trying to operate the mouse.

I can effectively kill the spastic ghost by uninstalling the serial mouse driver after XP has booted, but the problem comes back the next time I boot the machine.

If I disable the serial mouse driver instead of uninstalling it, the problem goes away and stays away, even after I boot again. This would be a fine solution if it was for just me, but I want to deploy this system to customers. I certainly don't want to try to explain all this to them, or to have them dinking around with mouse drivers.

I discovered (by Googling) that Windows supports a /NOSERIALMICE option within the BOOT.INI file that's supposed to prevent it from automatically detecting serial mice. I tried this option and it didn't work.

A second round of Googling revealed that /NOSERIALMICE was for Windows NT and that it's been replaced in Windows XP with the /FASTDETECT option. Unfortunately, /FASTDETECT didn't work for me, either. (In fact, it was already present in the BOOT.INI file when I started all this.)

Apparently this is not an uncommon problem. For example, quite a few links from Google described similar behavior when booting a Windows computer while it's connected to a talkative GPS device. These same links recommended /NOSERIALMICE or /FASTDETECT as the solution, but they don't seem to have any effect for me.

Can anyone suggest a different way to solve this problem? Or perhaps a hint about what I might be doing wrong with /NOSERIALMICE or /FASTDETECT?

Thanks,

-- Russ