PixHawk serial connection problem?

Folks,
So glad you are here!
I just purchased an original PixHawk and attempted to connect to a Windows 10 and Windows 7 machine with the same error.
“Error on link \.\COM4. Error connecting: Could not create port. Access is denied.”
any assistance is appreciated.
keep up the outstanding work and support!
Doyle

Have any luck? I have the same issue when trying to connect via radio. works over USB though :\