We have a VB6 program that reads GPS locations. Newer devices require port numbers > 16.
The implementation uses the Microsoft Comm Control 6.0 to manage serial port communication with the GPS device (described here: http://msdn.microsoft.com/en-us/library/aa231237%28v=vs.60%29.aspx">http://msdn.microsoft.com/en-us/library/aa231237%28v=vs.60%29.aspx). This software limits the value that can be specified for the communication port value to an integer from 1 to 16.
To support the new devices on Windows7 we need an alternative solution to the Microsoft Comm Control.