I recently updated my OS to centOs 6.4 in virtual box. Before update I had guest additions installed and everything worked fine. The screen resolution all was fine. After update to 6.6, the OS stopped booting. So as a workaround I saw in another website, I entered rescue mode and renamed xorg.conf file. Now the OS is working fine but the resolution is changed to the way it was before installing guest additions. Is there a way to get back the resolution without having to downgrade?