Bring the computer into safe mode by hittting the F8 key
while it is loading. What you need to clarify is that you
ONLY installed critical updates and not some drivers on
Microsoft's site. Their drivers are not recommended.
Anyway, when it comes up in Safe mode successfully, right
mouse button click on my computer and left click on
Properties. Go to the Advanced tab and then Startup and
Recovery radio button and then UNCHECK the box where it
says "Automatically Reboot". Reboot the computer and let
it come up normally and then start digging through the
event logs to find out the damage done. Also, check you
hardware manager to verify you didn't install a Microsoft
driver which has caused this to occur.