[HELP] Arduino board is not being detecting by my PC!

Hello everyone,

Recently, I had bought an Arduino Uno Board. It seem to be a clone, but it works perfectly fine in the first few days. Yesterday, when I am trying to test the IR receiver and at the moment when I am uploading the sketch, the Arduino IDE said the port (COM9) is not found. I was confused and tried to plug it again for a few times, but it still didn't seem to be working. I had searched for the problem and the solution in the internet for a while, but none of them helped. Apparently, the board is not broken or bricked, and the LED ON is turned on. The last sketch that I uploaded is the IR receiver testing sketch, which print the debug message in the serial, therefore I cannot determine if it is broken or not. In the next day (today), I test it again and suddenly it worked again magically. I was surprised and continue to program it again. However, after a few hours, it didn't work again. I was really worried and I don't even know if the Arduino is broken or not. :confused:

Useful information - The ON led is turned on - The pin 13 LED is lighted up, but it's extremely unstable. Sometimes it is very bright but it will gradually fade out. Really weird. - TX and RX pins are not turned on - When I put a LED to 5V and ground, it lights up perfectly fine. - When I plug it in to the computer, it the computer didn't play the amazing Windows 7 USB insert sound.

What I have tried to fix the problem: - Unplug and plug it again - Tried to use a different cable - Tried to use a different PC (Windows 10) - Tried to update the driver, however when I check the device manager, it didn't show any COM ports or whatever, also there's no unrecognized device. I have checked 'show hidden devices'. - Installed Arduino UNO driver (not able to start, error code 10) - Installed FTDI drivers (also not able to start, error code 10) - Reinstalled the whole Arduino IDE and drivers

Specs - Windows 7 Professional 64 bit - Arduino IDE 1.6.7

I guess - The board is shortened...? - The PC have some drivers problems?

Hope this can be fixed as soon as possible since I really wanted to program it and build awesome projects. Any answers are appreciated. :)