I purchased an R3 board yesterday from Radio Shack and ran example 1. The green LED behaved as expected; however when I changed the code slightly, I get the "not in sync" message. As I observe the board, the tx/rx LEDs do not appear to show the upload happening.
My computer shows only COM1, and the IDE shows that it us using COM1. The line at the bottom of the IDE says "Arduino Uno on COM1".
I have searched for the "not in sync: resp=0X00" message online and get lots of responses that boil down to "haven't a clue", and that's where I am now. It would appear that the board may be bad, but I don't have any way to confirm that.
We are going to need more information. Please post the sketch that you are trying to run, and point out the changes that you made from the original that was working.
What operating system is your computer using?
COM 1 is almost certainly wrong. Unplug the Arduino, reboot the computer, plug the Arduino back in, open the Arduino IDE, and see what COM port it shows.
I purchased a second board to see if I had a faulty board, but got same results.
I disabled the serial port in the BIOS and now the IDE (V1.0.1) cannot see any serial port.
I am running 64 bit Windows 7 Ultimate N, SP 1 with 2GB ram.
The Reference Guide under trouble shooting says, "On Windows 7 (particularly the 64-bit version), you might need to go into the Device Manager and update the drivers for the Uno or Mega 2560. Just right click on the device (the board should be connected to your computer)," but this is circular logic. How can I update a driver for a device that I cannot see?
So I am stuck. How do I get my computer to see the USB serial port?