This has only happened about 3 times in 50hrs of gameplay but annoying none the less. When it does it, it doesnt give any warning it just decides to quit itself (NOT CRASH) it quits then the steam deal opens. I dont know if this is because i occasionally alt tab out to turn hwmonitor, change volume etc. Or because of mods so heres my mod list from boss:

• Skyrim.esm
  
• Update.esm
  
• Imp's More Complex Needs.esm
  
• Populated Cities NPCListMaster.esm
  
• SoS - The Dungeons.esp
  
• SoS - The Wilds.esp
  
• Realistic Lighting.esp
  
• Realistic Lighting Patcher.esp
  
• Crafting300.esp
  
• dD - Enhanced Blood Main.esp
  
• IMCN - Overrides.esp
  
• itsatrap!.esp
  
• MoreRain.esp
  
• Portable Campsite.esp
  
• Real Wildlife Skyrim 0.1.esp
  
• StaticMeshImprovementMod.esp
  
• Tamriel Compendium.esp
  
• WiS IV - Heroes & Villains.esp
  
• SIM- NPC Additions.esp
  
• SIM - NPCSUBMITTED.esp
  
• DPArmor.esp
  
• Masters of Death.esp
  
• Weapons and Armor Fixes.esp
  
• Weapons and Armor Fixes - Hacks.esp
  
• Complete Crafting Overhaul.esp
  
• PISE.esp
  
• WiS IV - Rainbow mode.esp
  
• WiS IV - Water Wars.esp
  
• WiS IV - Fix FrostspiderGiant.esp
  
• DeadlyDragons.esp
  
• CutthroatMerchantsMedium.esp
  
• FollowerWander.esp
  
• Killable Children V2.2.esp
  
• killable_children_qp_aventus.esp
  
• killable_children_qp_nelkir.esp
  
• RealisticWaterTextures.esp
  
• RichMerchants_Less.esp
  
• Populated Cities.esp
  
• Live Another Life.esp
  
• MidasSkyrim.esp
  
• ReneersCrimeOverhaul.esp
  
• Balanced_Alteraton.esp
  
• Balanced_Conjuration.esp
  
• Balanced_Destruction.esp
  
• Balanced_Illusion.esp
  
• Balanced_Restoration.esp
  
• Balanced_Magic_Adept.esp
  
• Sabretooth.esp
  
• WiS IV - Blood Coins Slow.esp

?Unrecognised Plugins

• AssassinsCreedArmor.esp
  
• Disable Fast Travel Permanently - Carriages cost 10x more.esp
  
• WiS IV - leveld World X1.esp

It's Skyrim, not your mods.
I (and many, many) have the CTD (Crash To Desktop) also: just Skyrim suddenly closes without error or whatever and your back on your desktop.
This issue is a very well know Skyrim bug. It was very bad in the beginning but has been reduced dramaticly with the patches released sofar.
Yet the CTD still excist and I suspect that it will always be part of Skyrim. Only solution: hitting F5 to do a quick save a lot

Just one two aside sugestions. There are people reported in Nexus that Sounds of Skyrim - The Wilds and Realistic Water Textures conflict with each other, and it seems that even the load order does not matter... Probably is better you only choose one of them to your game.

I also think that Alt+Tab does not help too to the stability of the game. If I was you, I would avoid to do that.

If your alt tabbing to check various things pay attention to VRAM usage. It is possible you are exhausting it after a long play period and the game is closing due to it.

Had a couple of those even before I started modding. Mostly random it seems. Never use alt+tab. Close all applications before I start playing. 1GB VRAM. Windows 7 64-bit.

One I think was tied to a specific event. I had a kill move (decapitate) on a summoned Dremora when the game suddenly closed down.

Ok so its prob more the game then. Not getting rid of RWT or SOS, will live with this issue rather than get rid of them.

Def not vram issue, the max its gone to is 1.2gb and i have 3gb.
Looks like i'll have to put up with it and make sure i save often. Thanks for your replies ppl

...Ok. Just for sure, since you playing in a laptop, and if you play for a long time period, continue to pay attention to possible overheat problems with hwmonitor.

Best of luck!

No overheat problems either dude but thanks for the suggestion! i'll just see how things go!

If you're (you are = you're) going to use ALT-TAB, you should probably play Skyrim in a window for stability reasons. Also, you should check the game without mods to diagnose crashing problems before attributing them to the base game. I'm playing Skyrim under Windows 7 64-bit and I don't experience any crashes since 1.4. I play a relatively un-modded game, however. Outdated hardware drivers or GPU application-specific graphics settings can introduce stability problems as well.

I never experienced the bug until I had SoS with a loot and economy overhaul mods. Removed those and everything was normal. This has been and is being discussed on the mods forum.