Vista updated now i cant get my laptop to wor

Hello, my computer downloaded an update then it restarted and it stays on configuring updates then switches itself off. it then loops this. i tried all the F8 using the last known good configuration but it still does the same. when i brought my HP M550 it didnt come with any disks as it was already with vista home basic. i also cannot even lo gon to do a system restore. do you have any suggestions??