You will be able to find the missing Bluetooth option in the device manager. After that, restart your system, and you are done. You have to find the suitable menu option to update the BIOS for your system. Usually, the BIOS update option is in the advanced tab, but just like 'x', every BIOS is different. Every laptop's manufacturer defines its own key to change the BIOS settings. For me it was F2 as I have an Asus Vivobook X-series. Copy that file to any USB flash drive/pen drive.
Download the required drivers from the website of your motherboard's manufacturer.
If you don't know how to update BIOS drivers, you can follow the following steps.
Just find the latest drivers for the BIOS of your motherboard from the manufacturer's site and install it. You don't have to update Windows or install fresh one. After researching for 4 days, I finally found the solution. The problem is not due to drivers, fast boot or USB problems.
