Did your new computer come with a driver's DVD/CD? Try it.
Do you have access to another computer?
If so, bring a flash drive with you and download the drivers for your GPU card, from Gigabyte. Also,
For your monitor to loose signal like that it sounds like you could have an issue with the PSU (power supply unit). I know its a new pc. So I do not know why it should be drawing that much power unless there is a faulty ground in the PSU.
Also, what are the exact specifications, model number and brand name, please.
Is it stll under warranty? How old is your computer?
Thanks.
Cheers!
《♤》Sawuwaya / Spirit Wolfe 《♤》
Sent from my SM-G935P using Tapatalk