Windows XP (and sometimes Windows 2000) has a problem where a GPS is mistaken for a serial mouse, most of which died years ago. Because of this error, your mouse cursor will jump about the screen as if its tail was just caught in a trap. Frequently, Windows will also think you are randomly pressing the mouse button while this is happening which can lead to all sorts of nasty things. Here's how to fix it.

Since this article was written, more ways of solving the problem have been discovered. One somewhat technical, but very effective method of solving the "Crazy Mouse" problem once and for all is described on this Microsoft Help and Support page: http://support.microsoft.com/default.aspx?scid=kb;[LN];Q131976

Microsoft also has a tool that can be used to perform the fix as well. You can read about it here: http://support.microsoft.com/kb/819036

Microsoft has a long and technical description of the problem that is somewhat hard to find, and even harder to understand. Plus, it claims the problem is with Windows 2000 and has been fixed in a service pack. Of course, if you ask anyone with a GPS and Windows XP, they will probably tell you otherwise. You can see that article here.

One "simple" fix to the problem is to simply leave your GPS turned off until Windows XP has booted up. Not so simple if, like me, you leave your GPS on all the time and occasionally turn off the computer.

A much better fix, however, is to simply disable the automatic detection of serial mice. If you have a serial mouse, please donate it to a museum and get a real mouse. You'll want to use the wheel on a new mouse to zoom in and out while looking at charts in Coastal Explorer anyway...

To perform our simple fix for the standard COM1 and COM2 ports just click here, select Open, and answer Yes to the question about writing to the registry.

Please note: This works great on the few computers we have tried. We have received reports that it only results in an error message for some people. We don't know why, it doesn't make sense. It could be that they have a laptop with only one COM port, or even no COM ports. This patch will not work for USB to COM port adapters, or PC-Card (PCMCIA) COM ports, or BlueTooth COM ports, just the old standard COM1 and COM2 ports that every PC had in the good old days.