Error message when uploading 'Blink'

I have tried 2 usb slots and two leads and I keep getting the same error -

Arduino: 1.6.5 (Windows 7), Board: "Arduino Uno"

Sketch uses 1,030 bytes (3%) of program storage space. Maximum is 32,256 bytes.

Global variables use 9 bytes (0%) of dynamic memory, leaving 2,039 bytes for local variables. Maximum is 2,048 bytes.

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0xb2

avrdude: stk500_recv(): programmer is not responding

avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xb2

Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.

Did you select the right COM port in the IDE?

above error comes of two reason

1)tx & rx lines are occupied, wrong port/board being selected.in this case you need remove pin attached to tx & rx line

  1. bootloader got crashed. in this case you need to place uploaded bootlader ic or update bootloader using avr pocket programmer