I have just purchased an EtherMega. I had been able to download to the device from Vista for a while but when that became impossible (error: Serial port 'com 12' already in use ) I tried on a netbook running Windows 7. This was good for a while, but after coming back to work on it a couple hours later same problem as the other machine. No joy with the XP computor either. Checked using the PC's hardware manager and nothing else appears to be using the port concerned: it is shown allocated to the Freetronics eleven. I used the driver specified by Freetronics. An occasional flash issues from the RX LED by the USB socket during attempts to load the new program. The board is happily flashing away with the last loaded program. Thanks Jon, I suspect the problem may have been that I was using the Serial pins to drive an LCD and this was interfering with the downloading of the program. I have gone to Serial1 and so far no issue. Have yet to try it out on the other computer, but optimistic. It is possible I could load the program without the serial connection to those pins and reconnect, or perhaps the use of (the main) serial also opens another use of the same com port used to load the program. For now though will stay with Serial1 to be sure! shoots wrote: Thanks Jon, I suspect the problem may have been that I was using