Windows Update is going bonkers

Hello =)

I'm using Windows Vista Ultimate (OEM ver) and the thing is that Windows Update has gone bonkers :P

A normal boot for me:
*Loading Vista*
"Configuring updates..." //This goes on for like 5-10 minutes
"Shutting down..."
*Computer reboots*
*Loading Vista*
*Vista screen appears then goes black, reboots without any notice*
*Loading Vista*
"Configuring updates..." //This goes on for like 5-10 minutes again
"Welcome to Windows, please login"

This happens everytime I boot... And when Im using Windows it bugs me about Windows updates all the time. I've checked the control panel and it lists lots of security uptates marked as "failed".

Ny ideas on how to fix this?

Thanks! =)