Win7 Virtualization 16:9 or 4:3 problem

Hi.

I'm running Ubuntu 12.04.

I have 2 VM on my VirtualBox, both with win7 but probably from differente iso. I use one for work and the other for other stuffs. The one I use for work (and I didn't create) is showed in 16:9 and perfectly fit my screen. I can't do the same with the other.

Any help?


Thank You