At first, the Board seems to be working just perfectly fine (successfully uploaded a program , got the desired output and operations)but then after that numerous times of re-programming it happens when I tried to connect the Serial-USB port from the Arduino to my Computer again, unfortunately instead a pop-up message appears "USB Device not Recognized" really appreciated if you could help.
Plug the board in and open device manager. Im using win XP so for me thats start>settings>controlpanel>system.
Next click the hardware tab.
first thing on the hardware tab page should be device manager. From there, open the tree labeled PORTS (COM & LPT) and see if your arduino is recognized there.
Have you tried restarting your computer? Did you plug in the arduino while you had the serial port open? (dont)
When too much power is drawn from a USB port, it starts malfunctionning. I have this issue even with a small servo motor.
So, if you have anything connected to your Arduino, then disconnect everything and try again.