Android OxygenOS - Kapil Sharma

OxygenOS: Android Lollipop 5.1

Pre-requisite: Backed up all your smart phone data. 

Install 'Fastboot and ADB' on your Windows PC. 

Step 1: First flash your smartphone with recovery software. Download and save the TWRP file from here.

Step 2: Enable ADB Debugging mode on your smartphone. 
Click on Settings -> Developer options and enable ADB Debugging.  

Step 3: Switch off the phone. Enter Fastboot mode. You can do this on your OnePlus One by holding down the power button and the volume up button. When you see the fastboot logo, connect your device to your computer.

Step 4: Now on your Windows PC, start Command Prompt. In the CMD terminal, head to the folder where you have saved the TWRP recovery file you downloaded earlier.

Step 5: Type the commands as given below:  

fastboot oem unlock 
(You can skip this step if your phone’s bootloader is already unlocked).
fastboot flash recovery img
>. Image file should be the TWRP recovery image.
fastboot reboot

Step 6: Now your smartphone should reboot. Keep the smartphone connected to the machine.

Step 7: Head to the folder where you downloaded the OxygenOS file on your PC. You should see the file name oxygenos_1.0.0.zip. Unzip the file and you should be able to see the oxygenos_1.0.0.flashable.zip file being released.

Step 8: Copy oxygenos_1.0.0.flashable.zip to your phone’s internal storage.

Step 9: Once copied, detach the smartphone from the PC. Shut down the phone.

Step 10: Enter the recovery mode on your device. You can do this on your smartphone by holding down both the volume down key and the power button.

Step 11: Once you are in the recovery interface, the first thing you want to do is a factory reset. Again, you will lose all your data so please make sure you have backed up data before doing this.

Step 12: After the wipe, go to install and find oxygenos_1.0.0.flashable.zip. Confirm the flash. This will flash OxygenOS onto your smartphone.

Known Issues:

Files sometimes crash when uploading files to the cloud.
When printing images, printer service may stop.
Cannot hang up a call using headphone controls. (intermittent)
During system update, display of Wi-Fi/data notification may be incorrect.
OTG can only recognize FAT32 file system.
During system update, display of version number may be incorrect.
Files does not support multi-select deletes.
Files may crash when renaming image files

Download OxygenOS: http://oxygenos.oneplus.net/oxygenos_1.0.0.zip