how to solve -avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x20

Development Tools IDE 1.x
1

Dear All,
I m using arduino 1.6.8 in windows 7
I am facing the problem - avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x20

I am working on the UNO board and it was working fine but now it's not working..

All the hardware arrangements and software updates are ok.

Please let me know, how I can solve this issue

Thanks

2

Is this USB connected? Do you have anything connected to the RX/TX pins of your UNO?