It started 2 days ago. I was sneaking around in the southwest part of the map trying to infiltrate one of
the Forsworn ruins when suddenly my game started to not respond. It first started when i was goofing around
in the southeast just out of Riften in the mountains along a river... game stopped responding and i have a few
seconds to shut it down using the CTRL-ALT menu before it stalls my PC totally.

I've been playing all week without any errors, long hours of exploring and tying up quests because
my journal was getting a tad full. And all of the sudden, the game decided to start "Not responding".

Did Skyrim download a faulty update i don't know about or wtf is going on?.

A game shouldn't work flawless for 2 weeks just to totally stall on you for no apparent reason..

1) Verify files
2) System specs please
3) Sounds like some of your hardware may be failing

Maybe my GPU needs dusting.. but i did that a few months ago. i'll take a look.

/Edit: Nope. MY case if clean... mostly.

Could also be the CPU. I was getting lockups when my CPU fan needed to be cleaned out.

And just saw your edit. It could a failing component, not necessarily an overheating one. But, just to be safe, mind monitoring the temps of your components and posting back? If it's not that, maybe testing the hardware itself to see if something is failing could be in order...

Ye. I'll do a dust-clean. I like ur Avatar btw.

I enjoy it. ^^

Also, what's your OS? A memtest may be in order as well. XP needs an external program, Vista and 7 have a built in function somewhere.

Post system spec's.

Are you using any mods ...like SKSE ? SkyUI ?

XP Black. Modified by gamers for gamers. SP2. I was going to install SP3 but i recalled something being bad about it so i didn't.
AMD Dual5k+.
Geforce 8800GTS.
2G DDR2 Ram.

I run Skyrim flawlessly with some settings on low, like shadows, since that setting takes most juice. No AA or Tri-L or fancy stuff.
No mods except Arachnophobia and "Glow veins" for mining.

Make sure everything is fully up to date. There's nothing wrong with SP3. Also, try disabling the mods. And if those require the script extenders, make sure to remove those from the Skyrim directory.

Welcome to 1.4.21, I guess.

Does this happen with a new character? Could be a save that got corrupted. Which would also cause issues getting the game to launch again as it tries to display the screenshot from the most recent save.

So, archive your most recent save or saves, then see if the game launches, if it does, roll a new character and try that for a while. Note, if you do Autosaves, archive all your saves first so you don't over write your current Autosave while testing.

I've noticed something strange. Whenever i am somewhat close to any form of ruins with a lot of Forsworn.
Areas like : Lost Valley Redoubt, Red Eagle Redoubt, Gloom Reach, Crystal Drift Cave.

Last time i had these "lock up's", i reloaded and fast-traveled to a "secure" location, and the game stopped
"not responding" on me.

So i believe there is more that is going on then just my PC.

Have you tried waiting 30 in-game days? Could be a messed up spawn.

Have you tried the game with no mods selected? Have you checked to see if there are any updates to your mods? Have you used any of the third party tools that get mods to work like Wrye Bash or BOSS or any of those?

However, you can not evaluate the vanilla games performance and stability as long as you have mods on it. Otherwise, you are evaluating the game made with mods that came from an editor that was not made for this game and who knows what effect that is having on the game. The Official Editor comes out soon and until it does, I won't touch a mod for this game.