I think if it were me, my next step would be to disable any unnecessary startup items that run in the background. To do that, press Ctrl-Shift-Escape to open the Task Manager, then go to the Startup tab and right-click any items there and choose "disable". If you don't see the Startup tab, you might need to click "more details" first.
Disabling these startup items will make your computer start faster, and can prevent problem programs from running that block your shutdown later. It won't block you from using these programs on your own, they just won't start themselves automatically anymore.