Are you by any chance using Comodo (even just firewall) with avast? There is a massive glitch that causes NVIDIA drivers to fail with Comodo installed. Though not sure why uninstalling avast! would solve it.
Can you give more details on what other security software you (may) use, what is your OS exactly etc…
I’m aware of the issue on Windows 10, not sure if it also affects Windows 8.1. Basically, all you have to do is close the Comodo (CIS) GUI (right click on trey icon and exit). The app still runs protection, just interface won’t conflict with ForceWare anymore. Try that and see how it goes.
Yeah, the issue seemed too peculiar to be related to avast! because I’ve experienced it with Comodo first hand (I also use NVIDIA). I heard the issue is on Windows side and it’s getting fixed with the big anniversary update for Windows 10. Till then you’ll just have to exit Comodo GUI before you update ForceWare.