Hi, I am totally new to Arduino. I just bought a UNO and made some basic projects. Today I plugged it into my pc and there was a device descriptor error. So I reinstalled drivers, restarted the PC replugged the board still nothing. I noticed that instead of the usual blinking BUILTIN_LED was off but power was on. I thought there must be a bootloader issue so I did the "MINIMALIST WAY" as I had no other components. When I tried burning bootloader it just showed out of sync error.
Original or clone Uno? Which ttl-to-usb converter on the board?
What does your operating system think of your board? Which operating system.
What is the minimalistic way?
The built-in led will only blink if the last loaded sketch does this; it should however flash a few times in quick succession after a reset indicating the bootloader is active.
What was all connected when you worked with it before it failed?
You can't burn a boot loader that way; you need a second Arduino or a programmer. With a second Arduino, see below (taken from the page that you linked).
That's the TTL-to-USB converter; you have either an original Uno or a faithful clone.
If your last program sends data to the PC, that can be an indication. If that is the case, I'm reasonably sure that the 16U2 has died.
No, I didn't collect any data it was just a Bluetooth connection with a phone to make a BT car. Do I need another Arduino to flash bootloader or just remove the main chip and place it on breadboard moreover these components are not available to me is there any solution?
You need another Arduino (as shown in the image in post #5) or a programmer. But I doubt very much that burning the bootloader will help in this case. You can however try to burn the firmware of the 16U2 using the 6pin header near the 16U2; never done it myself.
The first one (post #8) will probably work; I'm not familiar with it. But you need jumper wires to connect it to the Uno; the flatcable that comes with it is 10-pin (2x5).
The second one (post #9) will not work as far as I can see.
Possibly the most flexible programmer that you can buy is Pololu USB AVR Programmer v2.1; it can also be used as a TTL-to-USB converter for e.g. uploads to ProMini or for an additional serial port (SoftwareSerial on your Uno).
