Maybe we need another rule about giving destructive advice? Dragon Tamer don't do that! hehe - had to say it.
Yes, after you install the NVIDIA driver update you should reboot immediately. I'm not sure why Nvidia doesn't just suggest it upon completion of the installation, but if you do not do this then Windows will be in an unstable state and any other installs would really mess things up.
Windows 10 has a "fix all" nuclear option where you can reset the entire OS. That will fix everything, but it will also leave you without any programs installed.