programmer not responding while uploading.. Please Help ..its Urgent.

Hey,

I have purchased new arduino UNO board and initially it was working very well i tested ethernet shield and many programs on it , but suddenly it started showing error while uploading.

I have tested many solutions like changing PC, changing port, verifying COM port and Board, Updating driver etc.

But again n again same error, I am really confused and running out of time, I need it resolved ASAP

Please help , Any tiny help will be appreciated.

Here is the error i am getting in Verbose mode:

//----------------------------------------------Error Message Start-----------------------------------------

avrdude: Version 6.0.1, compiled on Apr 3 2014 at 23:12:16
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2009 Joerg Wunsch

System wide configuration file is "C:\Program Files\Arduino/hardware/tools/avr/etc/avrdude.conf"

Using Port : COM11
Using Programmer : arduino
Overriding Baud Rate : 115200
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x01
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x01

avrdude done. Thank you.

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

//----------------------------------------------Error Message End-----------------------------------------

PLz Plz .. help.

Did you select correct board and programmer in IDE? Should be Arduino UNO and STK500v2.