Error in uploading sketch

Arduino: 1.8.2 (Windows 8.1), Board: "Arduino/Genuino Uno"

Sketch uses 444 bytes (1%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.

avrdude: arduino_read_sig_bytes(): (a) protocol error, expect=0x14, resp=0xf2
avrdude: error reading signature data for part "ATmega328P", rc=-2
avrdude: error reading signature data, rc=-1
avrdude: stk500_recv(): programmer is not responding
the selected serial port avrdude: stk500_recv(): programmer is not responding
 does not exist or your board is not connected

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

While uploading a sketch, i received this error.
my bootloader is working.
checked my com port and all my drivers are updated.

what should i do now ?