I have just bought a Cybertron PC with windows 8.1 and a Geforce graphics card preinstalled. For the past couple days I have been updating and installing software. Everything was going good for a day but not anymore. When I restart Windows I come to the login screen and login with no problem but after login the screen is black with a functional cursor. I can get to task manager and it will appear on the black screen. I have done quite a bit of simple troubleshooting including an earlier restore point. I believe it has something to do with the graphics driver update but I may be wrong. But to top it off if I leave the computer running for approximately 45 minutes the screen appears and works fine. I would run it this way but it's a new computer and would like to know what is causing this and find a fix. Any ideas out there?