Hi SRoy_v3558, Please repost this in the Software and Operating System, Linux forum for help. [URL] 
Hi, To setup dual boot I have used information from the following: Resetting UEFI to default brings back the USB boot option again. Any help is welcome. Thanks in advance: SRoy
(Redirected) UEFI option for booting from USB drive is deleted after Ubuntu 
16.04.2 (64 bit) installation (Dual boot with Windows 10 64 bit) on Dell Vostro 
3558.