Windows 10 is no dog. I've been playing with it in dual-boot configurations with Win 7, using the "Classic Shell" on one system and the default Windows desktop on another. The only thing that makes me uncomfortable about it is the decision to drop Media Center. A web-site for Media Center HTPC enthusiasts his offered a "hack" of the Win 8.1 MC version and directions to install it. It works flawlessly -- for now. So I continue to explore the alternatives available before killing my Win 7 partitions.
I also went through the troubles with the Windows Update malfunctions. My computer had been running at "idle" with 14% CPU usage for longer than I care to admit, showing the higher CPU usage arising from a SVCHOST instance -- a commonly reported symptom for this. So sometime around April, 2016, I took a closer look at the "installed updates" list and discovered there had been no successful updates since October, 2015.
The advice posted by others for this is spot-on. I had to try several different approaches, all available at self-help web-sites in recognition of the problem. And I had to "fix" two different computers which had that problem.
Since then, no problems. But if you miss the mid-month updates for a Win 7 install, you could run into this problem again trying to catch up.
On new clean installations of Win 7 SP1, you can expect the Update program to run for several hours until it detects some 200+ updates "available." A lapse in your patience will only complicate things, and lead to misery. After that, I divvy up the update list according to the date of issue, and install updates of different types ("Security . . " vs simply "update for Windows") in groups or segments.
But the essentials of it involve doing the installation of certain parts separately, as described by another poster -- including INternet Explorer. After that, I update the .NET Framework updates and other important items, followed by the groups of updates by date and type.
Then install IE 11
the Servicing Stack Update
Windows Update Client Update
then the Convenience Rollup
Then the June 2016 Rollup
I was prepared to install the Convenience and June 2016 Rollup as an alternative, but, as I said, with patience, I caught all 200+ of the updates the way they were originally available.