Having Issues with my Gaming Computer

About 3 weeks ago, I was finishing up playing Resident Evil Revelations 2. When I turned off the game, an update for Metal Gear Online PC came up. When I attempted to play an online match after updating the computer and changing some graphics settings) the online game started taking longer than usual to get in. When it finally let me in, parts of the game were not rendering properly. I ended up deciding to shutdown the computer, but as I was doing so, I noticed that it was taking longer than usual for it to shutdown. Rather than wait for it to finish shutting down on its own, I decided to manually turn off the computer.

By doing that, whenever I try to start up the computer, it now takes a very long time to get from turning on to getting out the Windows 7 loading screen (instead of taking less than a minute like it normally would). Once it gets out of that, the screen has nothing but black and white lines like this (except much thicker). I’m not sure what the main source of the problem is. I hope I can get some help solving this issue as I want to use my gaming computer again as soon as possible.

My computer specs:

OS: Windows 7 Home Premium x64 SP1
CPU: AMD Phenom II X6 1090T
RAM: 16Gb Corsair 1333MHz
GPU: Sapphire Radeon HD 7770 Crossfire
MOBO: Gigabyte GA-890FXA-UD5
PSU: Corsair TX 650W 80+ Bronze
Storage: Seagate Barracuda 1TB
Case: Antec Three Hundred Black Steel ATX Mid Tower

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