A. A. When NT boots its hardware detection component checks all hardware and updates the registry, sometimes it may not detect the mouse however it is possible to force NT to use a mouse on a given port:

  1. Start the registry editor (regedit.exe)
  2. Move to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Sermouse\Parameters
  3. From the Edit menu select New - DWord value
  4. Enter a name of OverrideHardwareBitstring and click OK
  5. Double click on the new value and set to 1 if the mouse is on Com1: or 2 if on Com2:
  6. Click OK and close the registry editor
  7. Reboot

For more information see knowledge base article Q102990 at http://support.microsoft.com/support/kb/articles/Q102/9/90.asp