^^ Nicely explained tutorial, @askey127! ^^
I am just a home user, not an expert.
But, unless this is a FRESH install of Win7, I think you can skip KB3125574.
Getting that particular patch installed has been a bit of trouble for some users, and it does not seem to be necessary to fix the WU client issue, at least on an existing Win7 SP1 system.
In my own personal experience (two Win7 boxes) and for many other users here, at sevenforums.com, at MS communities and in KB3200747, the two critical patches seem to be KB3020369 and KB3172605.
(If you search this section of the forum here at bleeping and elsewhere, you'll see many, many reports of favorable outcome with just those two patches. On a FRESH Win7 install, yes, KB3125574 does seem to matter, at least for some users.)
Please let us know how it goes, so that we can all learn.