hi, i have a sony vaio laptop that hasn't a serial COM port, so i have a serial to USB adapter to plug any serial devices i want. the thing is that the adapter went crazy the other day. each time i connected it to my laptop, it acquired a new COM port number, and after plugging and unplugging it several times, it stopped at COM port 11. the problem comes when i try to use a program that connects via serial COM port, because it only lists the first four ports COM1 - COM2- COM3 and COM4, and i want to change the serial adapter COM port to any number between 1 and 4, but i can't because they are being "used". i attach a print screen of the device manager and the COM11 port properties. under port settings ---> advanced, you can assign the COM port any number you want, but i have all the first 11 ports used and also 12 and 13, and if i try to assign one of the ports occupied, i get a message that a conflict might occur with the device or something like that. does anyone knows how to release or erase those apparently used COM ports??