Vista Service

I start up windows vista to find out that it takes a long time to start up, im using 2 gig ddr2 with q6600 (i dont know why)
well, it said i could not start firewall because a sevice is not running and it could not open it. A bubble in the system tray comes up and says windows cannot run a system service and i have to view it in event viewer.
So guess what, when i open event viewer, it says that a service is not running so it is unable to start.
I cannot get internet on that computer and I would like to really use it.