Yeah, I also hate the focus steal. And half the time the application isn't even actually read to do anything because it hasn't loaded the file yet so it forces itself to the foreground, steals focus and then tells me to wait for it to get ready. I feel like if the keyboard was in use recently, focus grab should just be blocked, actually, if the application hasn't loaded in 5 seconds load it minimized in the background and block it until the user explicitly maximizes it. It's somewhat of a security risk since I definitely have typed my password in the wrong window because of this.
Although I'm not sure this is a Windows specific aggravation, but it has been irritating forever.
I hate the complete disrespect that the update system has for my time. The fact that is slow as hell is aggravating enough, but it seems designed to force you to sit through it when it literally has no interaction options at all. I usually shut my PC down every day, and will click "install updates and shutdown" then leave while it says "Installing updates". But when I come back the next day and turn it on...it says "Installing updates..." or even more hilarious "Preparing to install updates" Why didn't this happen while I was driving home? Why do I have to watch this?
Instead you have to tell it to update and restart so it actually fully installs the updates, a process that takes from 0 to 12hours. But then it leaves your PC on after. Sometimes the update fails at the startup step and then it starts rolling it back! Again, why do I have to watch this? So the option you really want, update, restart, then shut off (and hope there aren't even more updates) doesn't even exist.
And don't get me started on Windows force closing all my documents while I'm on the toilet for 5 minutes to install an update. That might be a result of work's IT policy but it was still insane.