Undervolt is set as default, how to change?

[Laserninja]

Hi.

i set my GPU voltage to 0.90 instead of 1.12 to get lower temperatures, and it works fine when browsing or chatting etc as planned and i change back to original 1.12 when playing 3d games with no problems.
the thing is that for some reason it resets to 0.90 every time i reboot my computer, which causes unstable boots and the computer shuts down when im trying to reinstall my OS. i have no idea how this happened, and id really appreciate some help on how to set 1.12 as default voltage again

thanks /Linus