Support for Windows 7 and Windows 8 has ended.

[Freakazow]

That's nice, but I am running windows 10... whenever I try to launch the game, I get the above error.

[psykoteky]

This is also a common problem when running R* launcher or steam in windows 7/8 compatibility mode. I'd go doublecheck none of those are set as. Make sure to restart them if they were. Knowing R* - I'd likely expand that to check all .exe for R* launcher, and in the gta5 enhanced folder too - just to be safe (and because I'm too lazy to go test each one).

/goodluck