Sony laptop with a cracked screen: can I switch to external monitor at boot?

Above, but also, if the laptop has win 7 or vista if it was shut down improperly it will stop the booting process and ask you if you would like to start windows normally. you MUST press enter on some but not all machines or it will stay on that screen indefinitely, not all machines have a count down timer for this function. Start the machine, wait at least a minute until the hard drive activity ceases and press enter, it should then boot...that function key is probably not plug and play and requires the PnP feature with windows...just an fyi.