While playing Skyrim on my PC for the first time, I added a bunch of mods. During gameplay however, for some reason, the screen would go black for a few seconds at random moments and then go back to the game (I'm not sure if this is considered stuttering or freezing). It was usually outdoors, rarely indoors. This happened a lot, so I tried disabling a bunch of mods and testing it but I still had this problem.

After disabling every single mod I had, I gave up and re-installed Skyrim. Completely vanilla, with no mods. I made a new character and during the first part of the game it did the same thing, and a few minutes after that it even crashed completely. At first I played at Ultra, 8x anti-aliasing and 16x anisoptric filtering. During all of my test runs using the vanilla game I tried High with 2x anti-aliasing and 8x anisoptric filtering, still had the issue. Then I tried it at medium with 2x anti-aliasing and no anisoptric filtering... Still no luck. At this point I know it's not a performance issue, because I know for a fact my computer can handle Skyrim at Medium with no problems.

Then I tried downloading NVIDIA's latest Beta drivers (320.14). After that it still happened.

Any suggestions on what I should do? I've already ruled out my mods, my specs, and my drivers as issues (unless you can tell me otherwise) and I have no idea what to try next.

System Specs:

GPU: Gigabyte NVIDIA GeForce GTX 550 Ti
CPU: Quad-Core Intel i3 540 3.07GHz
RAM: 8GB
OS: Windows 7 64-bit