Do you have a virtual serial port SW of some sort loaded? Windows will only let a program connect to unique com port that is not shared by another program, so you need a program to generate these virtual serial ports and then tie two ends together, so data that goes one end goes out the other end as unique com ports . There are several virtual serial data programs out there, but we general recommend using VSP Manager from Steve, K5FR . Drop him a note, with you ham call requesting a copy, he includes instructions for connecting with PowerSDR. K5fr@arrl.net. .