Hello this is my first post so I apologize if this thread belongs in another area of the forums, but this seems like the right place. Before anything, I will give some general info about my desktop computer.. I know basic things about computers as I use mine a lot to play games/watch videos, etc. but not enough to troubleshoot effectively so I will give as much info as I can:

OS: Windows 8.1, 64 bit (6.3.9600 Build 9600)(?)
RAM: 8 GB
Processor: Intel Core i7-2600K CPU 3.40 GHz (X64 based), 3401 MHz, 4 Cores, 8 logical processors
Graphic Card: AMD Radeon HD 6900 Series
Motherboard: ASUSTek (I could not get the build name/model, it said its unavailable in System Information from Admin tools)
Monitor: AOC 2367M
Network Adapter: Realtek PCIe GBE Family Controller
Memory: I have two hard drives.. one is an SSD, the other is a regular one

So on my computer, I play a lot of games on a daily basis and while playing one on Steam (Sonic All-Stars Racing Transformed) one day, and at the time, I was running Windows 7. I was in the middle of a race and the monitor screen flashed and the game crashed. I thought nothing of it, until I launched Left 4 Dead 2. Every 10 seconds, the game would freeze for about 5 seconds with a black & white horizontal bar in the middle of the screen, and then go back to NORMAL.. but its funny, it only happens in the menu screens, but this does not happen during the actual game (this is only the case for Left 4 Dead.. everything else crashes one way or another). Then, the game alt tabs, and in the bottom right corner on the task bar, it says "Display driver has stopped responding and has recovered".. I googled it, and this was apparently a common problem especially for AMD users.

Around the same time this had started happening, I noticed that the Internet in our house (not just my computer, but the Xbox, and my mother's laptop) would lose Internet randomly for about 1-3 minutes, and then reconnect. It's very sporadic, and sometimes happens 1-3 times a day in total, or 3-5 times per hour.. I have not looked into this problem just yet

So I did the usual suggestions.. first I did a system restore, which did nothing..I updated the drivers, which took a lot of work, because it always said it needed an update after I had updated it almost 10 times through Windows Update AND the AMD website. I scrapped Windows 7 and bought Windows 8 because I had an invalid key and figured why not get validated. I obviously have tried leaving it off/rebooting it. I have been told I might need a new video card, but I don't want to spend the money on it unless I actually need it. I also tried running games in windowed mode which seemed to help the problem, but only a little bit, it would still crash just a little bit later.

After all of this, the next day, the freezing in the Left 4 Dead menus stopped.. I figured I had made some progress, so I launched Bastion and was able to play it without any interruptions at all. The game ran completely smooth. But then I started to notice that my browsers seemed to start slowing down and stop responding if I had more than like 2-3 tabs up.. I consider this an issue because I've had 6-7 tabs up while running games in the past with zero issues. I got bored of Bastion, so I played Sonic Racing again, and it crashed after about 20 minutes of play.

So, I figured I'd try another completely new game, to know for sure, and I tried Sacred Gold, a very old, easy to run game, especially with a good graphics card and processor (like me). I was able to get to the Character creation, and it'd eventually freeze up and crash, and I'd have to SIGN out of Windows and back in to end the program, because every program stopped responding once this specific game would crash. The next day I tried running Sacred Gold again and it couldn't even get to character creation anymore, it would get past the publisher screens and then to the LOADING screen, with a loading bar, halted at Type Manager (whatever that means for the game)

As of now, I can run World of Warcraft, Left 4 Dead 2, and Old school runescape.. everything else crashes in its own random fashion, and I've seem to run out of options.

I've tried uninstalling and reinstalling the games, and reinstalling Steam, to no avail. I first updated the drivers alone, then I tried completely uninstalling the drivers and reinstalling them, which did nothing. I've used CCleaner which also did nothing. I deleted a ton of games/pics/vids/etc. to free up memory on my regular hard drive.. nothing.

So tl;dr I could really use some help, and not just the standard suggestions you find on a customer service page, because I've tried everything I know how to do. It'd be greatly appreciated.. thanks in advance, I really don't have the $ for another card

EDIT: I also just downloaded Real Temp and I am using it now.. not sure what some of the numbers on the bottom mean, but I will give whatever info I can:
1) Right now I have Steam, Google Chrome (1 tab), and RealTemp running, and it seems like my computer is hovering around 38-46 Celsius
2) Now, I have Steam, Google Chrome (1 tab), RealTemp, and Sonic Racing in the menu screen, running, and my computer is hovering around 54-58 Celsius
3) Now, I have the same programs running plus World of Warcraft , and my computer is hovering around 63-66 Celsius

I don't know if the above stats are good or bad, but I figured I would post themYour TEMPERATURES are too high, so your problem may be overheating from dust collected on fans, surfaces and ventilation routes, or a failed fan. Pop off the side cover, take it outside (or you'll blow around a lot of dust indoors) and blow it out with your lungs. Don't breathe the dust, and don't touch anything inside unless you ground yourself first (no static). Plug it in and start it up without the cover so you can inspect all the fans. If you also own a laptop, blow those vents out while it's running. If you have a cat or dog, do this every year.

An outside possibility is that you got a bad electrolytic capacitor; see http://en.wikipedia.org/wiki/Capacitor_plague and it's aggravated by the heat. On the motherboard and video card, you'll see many devices that look like a little barrel with tops that have slits in them. These tops/cuts should be flat, not bowed up, nor have anything that has leaked from them (glue is OK). Any that are "blown up" have to be replaced (they have overheated and vented).

Inspect the mobo and video card components and plugs for burning, discoloration, burnt smell or anything that looks odd. Some people suggest checking the Windows Error Logs (Google it) but that may be a long shot here unless you still have a driver problem. Have you tried running in Safe Mode? (It's called something else in Win8, Google that, too.) You could check the RAM and any other component that's in a socket to make sure it's fully seated as long as you don't break anything (this is a pretty long shot, too, but any of the things I've described can cause your problem).

Last possibility, your power supply is not providing a solid 5 volt line with no ripple, or the power supply (or mobo) has a faulty ground SOMEWHERE. If you can check it with a meter, the black wire goes to the chassis (ground) and the red wire goes to any one of the pins in a large plug on the mobo that carries 4.75 to 5.25 VDC, no more, no less. Also check for AC voltage on the same pin, it should be no more than a tiny fraction of a volt. If the 5-volt line is too high or too low or there's too much AC ripple, you'll need a power supply -- it's impractical to repair them.

I use SpeedFan to check temperatures because it shows a flame graphic beside too-high temps.Thank you very much for the reply.

This is a lot to look into but that's a good thing, that means I'm bound to find a solution. I think the first thing I'll do is open up the tower like you said, I have a feeling it has something to do with dust, as I've cleaned the outside vents with a keyboard duster, but never the inside.. probably clogged. If that isn't the issue, I'll check out some of the other things you said. 

Again, I really appreciate the help, thank you. Should get a reply from me within the next day or two on the situation if you decide to follow up.It's your connection...
Or on they're end.