Hi all, I want to connect an atmel microcontroller to PC using USB. I use CDC driver to emulate the serial port and a small program in VB 6.0 to send and receive some data. The enumeration is fine, the PC load the driver the port is COMM3, same settings in MSComm in VB. The problem is that it only run one time but no more, after I tried next day the enumeration process was ok but it could not receive any data, neither micro or VB program. I decided to run it in other computer and it works. I have tried 2 CDC drivers, from micropic and ATMEL buy no way. Does anybody know if there is any conflict with any other application? maybe ActiveSync for PDAs? I desinstalled it but did not work. Thanks, Alfredo.