Let's get one thing out of the way right now which can cause update problems.
I need for you to verify that you have a genuine Win 7.
If MS thinks you r version is not genuine, this can cause all kinds of problems with updates. They so not genuine, then you end up with update problems.
Do me a favor. WIN + Pause/Break | bottom right., you should see a Genuine Microsoft display. Iif not then, have you activated your Windows?
If not, then activate.
WIN is the key with the wavy microsoft flag.
I'n not saying that this is the problem, I just want to make sure that we don't waste your time.