The OP was complaining about the
speed of his Windows 10 and the constant updates which change his install. He wasn't complaining about
crashes. You do need a fairly robust system to use Windows. The OP mentioned spinning so I assume he still uses a hard drive and not an SSD or M.2 NVMe.
This is what I recommended to anyone for an upgrade in my reply. Even a 7200 RPM hard drive will be slow. If the OP is using 4 GB RAM or less, chances are his PC was constantly accessing the Windows swapfile, something which will greatly slow any PC. That could be the thrashing he was mentioning.
If you want a true multi-monitor trading desktop, you really need to buy at least a 4 core/8 thread CPU, 32 GB quad channel RAM, and an M.2 NVMe. Trading platforms, browsers, etc..., they all take a large amount of RAM.
There has been a lot of excitement regarding the new 7nm AMD Zen 2 line of CPU's expected to be announced May 30. You can probably buy them in October so wait until then for them to work out all the bugs in the BIOS and Windows. You may be able to buy a 12 core/24 thread AMD Zen 2 CPU for under $400. The new 7nm AMD Zen 2 is expected to be faster than Intel's 14nm i9 CPU.
Be sure to disable all Microsoft Windows 10 Telemetry to the extent you are able. Keep an eye on your open ports to see if Windows 10 is sending any data and when. I don't think you can do anything about the automatic Windows updates. At best, all you can do is delay them. I haven't searched for any solutions though.
I use Windows 7 Pro on my 5 monitor, i7, 16 GB RAM, 512 GB SSD desktop. 16 GB RAM is the most my desktop will take.