Exactly what I thought. OK, you switched to Unstable branch (this 495 driver is only available there for now), updated, didn’t reboot, and installed Windows. then you noticed the issue only after rebooting from your Windows installation.
If your GPU isn’t supported, for now you can simply remove the Nvidia driver and run with nouveau driver (video-linux in mhwd).
sudo mhwd -r pci video-nvidia
sudo mhwd -i pci video-linux
Alternatively, you can go back to Testing branch, force downgrade of all packages, and prey for no dramatic breakage.
sudo pacman-mirrors -a -B testing
sudo pacman -Syyuu
On a side note, your issue points to things you do wrong:
- you update your system, and don’t reboot
- you don’t seem to have a backup solution for when breakage happen (use TimeShift, configure it to do not do auto snapshots, and do one manually before a big update to be able to go back to previous system state if something goes wrong)
- you don’t consult the appropriate forum despite using the most breakable branch (where the info is available about this issue since yesterday)
- you didn’t post relevant info about your system in initial post which would have instantly shown the issue
Keep that in mind for the future it will help having less issues, and having instant solution most of the time.