New GPU and computer wont start

[bodidad]

So i got a new Geforce gtx 1080 with water cooling gpu and it wont start installed but uninstalled it works fine. i have windows 7, 16gigs of ram, 650psu, and my motherboard is a msi 880gma-e45. Not really sure what to do about it.

 

[mangaman]

Make sure all of the cables are plugged into the GPU, including the two 8pin connectors.