Arduino uno stopped working

the power and the led in pin 13 just keep glowing.the IDE doesn't detect the board.reset button is also not working.

I use windows 7 64 bit.the following message is displayed while uploading
the last sketch uploaded was-

#include <Servo.h>

Servo myservo; // create servo object to control a servo
// twelve servo objects can be created on most boards

int pos = 0; // variable to store the servo position

void setup() {
myservo.attach(9); // attaches the servo on pin 9 to the servo object
}

void loop() {
for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
// in steps of 1 degree
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}
for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}
}

Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
Invalid library found in C:\Users\ABC\Documents\Arduino\libraries\Fade: no headers files (.h) found in C:\Users\ABC\Documents\Arduino\libraries\Fade
Invalid library found in C:\Users\ABC\Documents\Arduino\libraries\servo1: no headers files (.h) found in C:\Users\ABC\Documents\Arduino\libraries\servo1
Invalid library found in C:\Users\ABC\Documents\Arduino\libraries\sketch_oct11a: no headers files (.h) found in C:\Users\ABC\Documents\Arduino\libraries\sketch_oct11a
Invalid library found in C:\Users\ABC\Documents\Arduino\libraries\temp: no headers files (.h) found in C:\Users\ABC\Documents\Arduino\libraries\temp
Invalid library found in C:\Users\ABC\Documents\Arduino\libraries\Fade: no headers files (.h) found in C:\Users\ABC\Documents\Arduino\libraries\Fade
Invalid library found in C:\Users\ABC\Documents\Arduino\libraries\servo1: no headers files (.h) found in C:\Users\ABC\Documents\Arduino\libraries\servo1
Invalid library found in C:\Users\ABC\Documents\Arduino\libraries\sketch_oct11a: no headers files (.h) found in C:\Users\ABC\Documents\Arduino\libraries\sketch_oct11a
Invalid library found in C:\Users\ABC\Documents\Arduino\libraries\temp: no headers files (.h) found in C:\Users\ABC\Documents\Arduino\libraries\temp

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