Windows Update causing problems?

Hello. My computer has an ongoing problem: Everytime my windows 7 updates, it makes my internet unavailable. I am still connected, but i cannot access the internet at all. After many troubleshoots, i have narrowed it down to the Firewall, but i do not know how to fix it (troubleshooting suggests it could also be the DNS). I have Done numerous system restores to a date before the update, but that is just a temporary fix. What do i do?:cry

 

well as helpful as that is, I would like to do a factory reset. I do not have much personal information, so i wont be at a total loss. I have a dell inspiron laptop how would i go about doing that?