if read the internet a little and i think its the fault of dell every time someone is saying he/she got this crashing they say it a dell computer ive got a dell to and i got the crashes to i know its 1 bad update i read somewhere it was update KB943899 i know its not a securety update im going to delete that update and then restart my laptop will add if it worked added problem solved its doesn't crash anymore when i try to start vista so if your computer crash when booting (starting up windows vista) go to configuaration then updates history of updates and then installed updates delete the update KB943899 there if its a bit hard to read sorry my english isn't that good