Game "almost" crashes, freezes randomly afterwards

[Chaz_the_Camper]

When I'm playing Oblivion, it works fine for the first few minutes, then freezes up (the sound stutters too), and displays a window saying "This game has stopped responding". Now, I do Ctrl-Alt-Delete to enter task manager just so I can click the "Close this game" option. When I do that, it actually brings me back into the game as if nothing had happened, but unfortunately, the game freezes at random intervals (and if I'm fighting hand-to-hand, I get stuck in the blocking position and can't get out.)

Specs are as follows:

Windows 7 Home Premium 64-bit
Intel i5 750 (Quad core, 2.66GHz, 8MB cache)
4GB of RAM
nVidia GeForce GTS250 (1GB VRAM)

I have a sneaking suspicion that it's something to do with the fact that I'm using a quad-core processor, but when I try and enter task manager to set the core affinity, Oblivion crashes and any attempt to set affinities gives me a "Permission denied" error, despite me having Admin status on my computer.

Any thoughts?

[JagFel]

I'm on a quad core and have no troubles.
Any mods installed?

[Chaz_the_Camper]

Apart from the DLC that comes with the Deluxe version (Shivering Isles, Knights of the Nine and the 7 other expansion packs), I haven't installed any mods yet.

[JagFel]

May want to try installing the UnOfficial patches/mods, or the Crash Prevention mod. See if they make a difference.

[Threesixtyci]

Some have had luck with installing K-lite... you may want to give that a try. I've had K-lite already installed on my PC for years, now...

[Chaz_the_Camper]

Hmm. Strangely enough, the game seems to work fine if I go into the folders and change both Oblivion and the Launcher to Compatibility Mode (Windows XP Service Pack 3). Unfortunately, by doing that, it makes the game unplayable from Steam (The launcher starts, but almost all of the options, "Play Oblivion" included, are grayed out), but hey, I have no problems with that, I can just run the game right from the common/Oblivion folder, no bother. ^^