Serial or USB Clock Problems Under Windows

If a clock which has been connected via USB or a serial port can't be accessed by its driver software then eventually the device is already in use. This can be by due to a different program which has indeed opened the device, or even by Windows itself which mistakenly assumes it a found a new mouse device.

When Windows starts up it checks the computer's serial ports to see if a serial mouse is connected.

If a serial clock or GPS receiver has been connected to one of the ports, and the device just sends some data when Windows checks that port for a serial mouse then Windows may mistakenly assume that it has detected a serial mouse, and creates a mouse device in its device manager.

As a consequence, the driver software for the serial device is then unable to access the device since the serial port is already in use by Windows' mouse driver.

The same problem has been reported if a new USB device is connected, in which case the Windows Plug'n'Play subsystem checks if the new device is a mouse.

This is very annoying since everything may work well for a long time, even across reboots, until the problem occurs for the first time, and then things suddenly stop working.

This problem has been reported for many Windows versions including old Windows NT, 2000, XP / Server 2003, Windows 7 /Server 2008, etc.

There are a number of Windows support pages which suggest specifying boot parameters noserialmice and/or fastdetect by editing the boot.ini file used by older Windows systems, or running the bcdedit tool for newer Windows versions, e.g.:

• How to Disable Detection of Devices on Serial Ports
  https://support.microsoft.com/en-us/kb/131976

• Editing Boot Options
  https://msdn.microsoft.com/en-us/library/windows/hardware/ff545492%28v=vs.85%29.aspx

However, this doesn't seem to help in all cases.

A good workaround seems to be to look up the wrong mouse device in the Windows device manager, and just disable it.

If the device is disabled then Windows knows a device similar to a mouse might be available or not, but should not be used anyway. As a consequence no mouse driver is loaded for this device, and the device is available to the real driver software.

If the erraneous mouse device would be deleted/removed instead of just being disabled then Windows might detect a “new” device next time, and create another serial mose device, so the problem would arise again.

There are more potential solutions like editing the registry, etc., but these may help or not, and are commonly depending on a specific Windows versions, so it might be worth doing an internet search:

• https://www.google.com/?q=noserialmice+bcdedit

— Martin Burnicki 2016-12-22 11:49