[chirp_users] Com Port Access Denied

I recently purchased a new Baofeng BF-F8HP radio, and an FTDI cable from AnyTone. No matter what software or drivers I use, and no matter which Com Ports I use, I get the same warning [ "An error has occurred, could not open port Com XXX: [Error 5] Access is denied."] and am unable to connect to the radio. I have tried this on both my Win 7 Pro and my Win 10 machines with exactly the same results. I also have noticed that no matter what Com Port I choose, I get a message that some other application is already using it [I have tried ports all the way from 14 into the low 100's], which of course, I can hardly believe. Any help would be much appreciated.

Mark