The Sims 4 keeps freezing whole computer?

I just downloaded The Sims 4, Get To Work, and Get Together, as well as the fix for Get Together. I then went to apply the Ultimate Fix, and the game starts fine. However, before you even get to the main menu, it freezes up and refuses to be shut down by any means (Task Manager, Alt+Tab, ect), requiring me to restart my computer. Is anyone else experiencing this issue?

You didn't install it correctly. You should install it in order Base Game->Get to Work->Get Together->Hotfix. There's no need to apply Ultimate Fix because it's alerady included when you install Get Together. I had exactly same problem and it was applying Ultimate Fix over fully installed game, so to solve that follow these steps. When you're installing The Sims 4 use this guide. Now, uninstall The Sims 4 using Your! Uninstaler Pro. Uninstall it using Super Mode and then reinstall The Sims 4.