I just had this response problem: avrdude: stk500_getsync(): not in sync: resp=0x00. I had seen this before when I first started with Arduino's. My laptop came with Windows 7, but I had to down grade to XP to support some equipment where I work.
Here is how I was able to get it to work:
I went into the folder: D:\arduino-1.0.1-windows\arduino-1.0.1\hardware\arduino and opened the boards.txt file.
I changed the line: uno.upload.maximum_size=32256 uno.upload.speed=115200
to: uno.upload.maximum_size=32256 uno.upload.speed=19200
Then I got this error: avrdude: stk500_getsync(): not in sync: resp=0x80
I changed the upload rate to 57600: uno.upload.maximum_size=32256 uno.upload.speed=57600
This fixed my problem and my LED is now blinking. Evidently the upload speed is different on this laptop because my other laptop does fine with the 115200 speed.
I hope that this will help out others with this problem.
charlie