taking backup of running desktop

[Tapas Mishra]

I have a habit of developing device drivers for some reason.I do  use
a virtualization environment using VirtualBox,Qemu.
Many a times I have to format my laptop then in such situations
installing again the previous programs and making same changes to the
configurations is very painful.
Is there some way I can make some sort of backup which I just need to
install on my existing system and get all previous things immediately
installed without going to install and setting of a lot of other
applications and settings.