If I was a guessing man (and since I'm not a trained IT guy, I am just that), I'd guess that your Windows 10 download got stifled by a buggy router and/or IP block.
Before I went to fiber-optic net, I had Time-Warner Cable internet (and before that, DSL, and before that, standard dial-up). My actual IP was a regional group called Internet America (ironic, eh?), but Time Warner was the deliverer of what Internet America provided. What could possibly go wrong?
As my internet usage ev olved, I noticed that more and more, updates or any other potentially larger downloads would seldom complete, they would time out first. IA said it was a TW issue, TW said it was an IA issue, and when I finally got them both on the phone simultaneously, it was TW who ended up putting me on hold never to return and IA saying SEE? We told you this was what it was.
And what it was was that somewhere in the TW chain, which was really just a block or two up into my house, they were throttling/limiting/whatever downloads of over a certain size that didn't complete in a certain amount of time. The more prime time you were, the less of a window they gave you to complete before stalling you out.
I switched to Verizon Fios about a week later and as if by magic, all my downloads started happening in a nice, timely, and most importantly, complete fashion.
You're in kind of a semi-rural area, right? Between that and the probably buggy router waiting to die, I think that's a safe-enough guess as to what went wrong with that.
But - now you've got a 2011 version of 7 racing against itself to keep up with god knows how many updates. some of those newer updates are rendered obsolete by subsequent ones, so don't wig on the counting system. And preferably, don't shut down in the middle of an update until the computer tells you to (and it will). It's not supposed to make a difference, but hell, this is Microsoft, they sort of expect you to think for yourself sometimes, and if you guess wrong, hey, that's what Apples are for!
I skipped my 7 updates for about a year and a half, and when I got around to doing it a few moths ago, yeah, it took several gothroughs until they finally got caught up. But they did. You just gotta leave it alone to do its thing, it won't respond to imposed deadlines and shit like that.
And oh yeah - check to see that, for right now anyway, you're just doing the "critical"(?) updates and not the "optional" ones. That will save you some time, and you can always come back later to see what of the optional ones you really feel are desirable.
I've not yet been extended the "invitation" to update to Windows 10 (they're rolling it out in segments), and I can't say I've heard a LOT of horror stories about it...and some people are actually quite please, especially those that got suckered into 8. So if you feel like you NEED to update, Microsoft will be more than happy to take your hit on their website and run like hell with it.
As for iTunes, can't help you there. I stopped updating mine a long time ago, since it more and more got cross-platformy, like what, you DON'T have an iPhonewatchtv yet? Well, you SHOULD if you want this shit to work like we want it to! I just use it for my iPod, for how much ever longer that's going to last. I'm told that if you know somebody who knows how to do such things, there are places to go to get older versions. But that's jsut what I'm told.