Troubleshooting the Serial Mouse

Serial mouse does not respond

The COM settings the DTR settings and possibly the interrupt settings need to be set properly on the serial card Check with the manual to be sure you have the correct settings.
Remove all other serial ports to be sure they are not conflicting with the mouse.
Try a different mouse on your computer. If it woks the original mouse is probably faulty and needs to be replaced or repaired
Try the mouse on another computer if it does not work the mouse is probably faulty and needs to be replaced or repaired.