COM Port Problems under Windows 7 and Later

article #677, updated 1113 days ago

If you have a problem with COM port devices under Windows 7 or later, your system may think it has autodetected it as an old-style RS-232C port mouse! To fix that, regedit here:

hklm\SYSTEM\CurrentControlSet\Services\sermouse

and change the DWORD Start to 4. This prevents the autodetection of COM-port mice!

Contributed by the excellent Brad Hollingsworth.

Categories:   Windows OS-Level Issues   Hardware