The PCIe Express version of the board uses an interface chip that has two PCIe serial COM ports. In some cases Windows assigns these COM ports to really high numbers - like COM 41 & 41.
The DLL we supply to auto-scan for our board stops searching at COM 25 to keep the search time reasonable. Therefor it fails to find an installed board.
The fix is easy.
Go into device manager and re-assign the two COM ports to something like COM16 & COM17. Windows may show a warning - but will let you change them unless there is truly another COM port there.
We are not sure why Windows assigns new COM ports such high numbers sometimes.