I have a strange behavior when I install virtualbox on my windows8 laptop: Cold boot (windows8 restart) will then fail, whereas shutdown (fast boot enabled) or suspend still work fine. Laptop is an HP G6 with an SSD installed with 64 bit windows 8. Prior to the virtualbox install all three actions (suspend/shutdown/restart) work fine. If I install virtualbox (simply installing, not creating any VM), then the next restart will trigger an "automatic repair" screen at boot. Will never terminate. Only way to fix is to escape + F11 and restore a previous restore point. If instead I say shutdown (I have fast boot enabled) or suspend, the system will restart fine at next power on or resume. Any hints on what the system checks on at cold boot time ? Something that the virtualbox install could break ?