Note:If driver already installed no need to install again.
Adb & fastboot 1 click Driver Download
Note: Before flash unlock yur bootloader after flash complete lock bootloader commds below
fastboot oem unlock
fastboot oem lock
Nexus 4 5.0 (LRX21T) Factory Image Download
Nexus 5 5.0 (LRX21O) Factory Image Download
* Extract the firmware zip 1st
* After Extract yu vil get a single file
* Change tat files extension .tar or .rar (if change as rar use 7zip to extract it)
* Again extract it after change the Extension yu vil get files below given in the picture.
* Connect yur mob in fastboot mode
* Run the flash-all.bat
Root File For Nexus 4
Root File For Nexus 5
* Enable usb debugging
* Connt yur device to pc
* Goto extracted root files folder nd run the root-window.bat file
* Follw the on screen instruction after that.
Note: Before if not bootloader unlocked it vil unlock yur bootloader so take backup all files