sony laptop problem with windows updates

Got Viao VGN-Nr10 laptop with Vista Home Premium. Problem is with automatic Windows upadates which interupt in the middle of using the laptop and then closes down to restart. Problem greatest on Hotmail and Word with part composed work where you loose it!!. I have XP on a PC and it automatically updates on shut down - no problem. Can't find such a setting in Vista. Should I just upgrade to W7? Any suggestions?