VirtualBox VM fullscreen [FIX]

You may tried all methods to make your Linux VM in Virtual Box full screen but nothing worked.Right?

 I also encountered the same issue, so here is the solution that worked for me.

I was using Kali Linux and by default the guest additions comes preinstalled but that didn't solve my problem. I was not getting the window full screen.

The below screenshot is before solving the issue. I tried to install the guest additions manually and noticed that the OS was unable to find the kernel headers. 

 Try the...