Pb with serial ports NUC DE 3815TYKHE

Hi

I am unable to use the 2 serial ports on the NUC DE3815TYKHE ( running windows 7 embedded).

I can see the 2 ports when I go to the device manager, however when I try to connect to any of them  I get the message " port used by another program", re installing the driver didn't help either

Any suggestion

Thanks