After its release and for about an year I used to play vanilla Skyrim without any problem with all the graphic settings at lowest(except for textures and decals which are on medium) since I have a rather weak pc:Intel Pentium Dual Core E2200,2GB RAM,Ati Radeon HD 5450 2GB(1,7 actually) and Windows 7 Ultimate Edition.Even after modding it with +150 mods(no textures and too heavy stuff,mainly gameplay changes,more immersion etc) I was able to play with 25-30fps at 800*600 resolution(For some strange reason I lagged more on first person than on third).But before some months after installing for one more time the game I started to use other mods too(I removed of course about 50 other mods and was left with about 120) and also used the HiAlgoBoost which let me to set the resolution to 1024*768,increase view to distance to maximum along with the textures to high).For some hours everything worked fine until I reached Whiterun and the game started to constantly CTD.After talking with the author, checking my other mods and lowering the settings we reached to the conclusion that it was a memory allocation problem and so I abandoned the game.In the last week I reinstalled it(I also have all the dlc) after finding out about Safety Load and installed some mods too(pretty much the same with before with some changes).My mod loading list is the following:

(0 -> 0) Skyrim.esm

(1 -> 1) Update.esm

(2 -> 2) Dawnguard.esm

(3 -> 3) HearthFires.esm

(4 -> 4) Dragonborn.esm

(5 -> 5) Falskaar.esm

(6 -> 6) ApachiiHair.esm

(7 -> 7) ApachiiHairFemales.esm

(8 -> 8) alchstone3x.esm

(9 -> 9) ClimatesOfTamriel.esm

(10 -> 10) ETaC - RESOURCES.esm

(11 -> 255) hdtHighHeel.esm

(12 -> 11) JSwords.esm

(13 -> 12) SPIKE.esm

(14 -> 13) Unofficial Skyrim Patch.esp

(15 -> 14) Unofficial Dawnguard Patch.esp

(16 -> 15) Unofficial Hearthfire Patch.esp

(17 -> 16) Unofficial Dragonborn Patch.esp

(18 -> 17) ClimatesOfTamriel-Sound.esp

(19 -> 18) Immersive Sounds - Magic.esp

(20 -> 19) Improved Combat Sounds v2.2.esp

(21 -> 20) BrighterTorchesBiggerMagelight.esp

(22 -> 21) TradeBarter.esp

(23 -> 22) ApachiiHelmetWigs.esp

(24 -> 23) CalienteVanillaArmorTweaks.esp

(25 -> 24) Chesko_WearableLantern.esp

(26 -> 25) DungeonQuestAwareness.esp

(27 -> 26) GuardedBorders.esp

(28 -> 27) HunterTraps.esp

(29 -> 28) Immersive Battles.esp

(30 -> 29) Immersive Brigands.esp

(31 -> 30) Immersive Dawnguard.esp

(32 -> 31) Immersive Dragonborn.esp

(33 -> 32) Immersive Factions.esp

(34 -> 33) Immersive Mercenaries.esp

(35 -> 34) Immersive Patrols.esp

(36 -> 35) Immersive Travelers.esp

(37 -> 36) Immersive Werewolves.esp

(38 -> 37) sanctuarycleanup.esp

(39 -> 38) Skyrim Immersive Creatures.esp

(40 -> 39) Skyrim Immersive Creatures - DLC2.esp

(41 -> 40) WetandCold.esp

(42 -> 41) WetandCold - Ashes.esp

(43 -> 42) JSwords_Load_Screens.esp

(44 -> 43) RaceMenu.esp

(45 -> 44) RaceMenuPlugin.esp

(46 -> 45) SkyUI.esp

(47 -> 46) iHUD.esp

(48 -> 47) DK_Armor_By_Hothtrooper44.esp

(49 -> 48) HentaiVoidArmor.esp

(50 -> 49) JSwordsDistributionBalancePlugin.esp

(51 -> 50) Dr_Bandolier.esp

(52 -> 51) DeadlyDragons.esp

(53 -> 52) SkyRe_Main.esp

(54 -> 53) SkyRe_Combat.esp

(55 -> 54) SkyRe_EncounterZones.esp

(56 -> 55) SkyRe_EnemyAI.esp

(57 -> 56) SkyRe_EnemyScaling.esp

(58 -> 57) SkyRe_StandingStones.esp

(59 -> 58) SkyRe_SIC Crossbowfix.esp

(60 -> 59) AlchemistsHiddenValley.esp

(61 -> 60) CAMP.esp

(62 -> 61) CornerofTheSkyrim.esp

(63 -> 62) Falkreath Graveyard.esp

(64 -> 63) Hunting in Skyrim - No Perks.esp

(65 -> 64) quest into the depths.esp

(66 -> 65) Run For Your Lives.esp

(67 -> 66) When Vampires Attack.esp

(68 -> 67) Quest_SeaOfGhosts.esp

(69 -> 68) Skyrim School of Witchcraft and Wizardry.esp

(70 -> 69) The Paarthurnax Dilemma.esp

(71 -> 70) Undeath.esp

(72 -> 71) Wyrmstooth.esp

(73 -> 72) BurntCorpse.esp

(74 -> 73) Civil War Repairs.esp

(75 -> 74) Deadly Traps.esp

(76 -> 75) FalskaarDawnguard.esp

(77 -> 76) Guard Dialogue Overhaul.esp

(78 -> 77) Headtracking.esp

(79 -> 78) OpenFaceGuardHelmets.esp

(80 -> 79) Sickly Diseases.esp

(81 -> 80) TheChoiceIsYours.esp

(82 -> 81) TheChoiceIsYours_Dawnguard.esp

(83 -> 82) TorchRadius.esp

(84 -> 83) ETaC - Complete.esp

(85 -> 84) ETaC - Complete HF Patch.esp

(86 -> 85) ETaC - Smelters.esp

(87 -> 86) Populated Cities Towns Villages.esp

(88 -> 87) Provincial Courier Service.esp

(89 -> 88) ClimatesOfTamriel-Dawnguard-Patch.esp

(90 -> 89) ClimatesOfTamriel-Dragonborn-Patch.esp

(91 -> 90) ClimatesOfTamriel-Dungeons-Hazardous.esp

(92 -> 91) ClimatesOfTamriel-Interiors-Cold.esp

(93 -> 93) Better Vampires.esp

(94 -> 94) ToL_Core_by_Brevi.esp

(95 -> 95) MidasSkyrim.esp

(96 -> 96) ConcentrativeFireFrostShoutsforPlayer.esp

(97 -> 97) ImprovedSneakDetection.esp

(98 -> 98) The Dance of Death - Ultimate Edition.esp

(99 -> 99) Crimson Tide - Blood.esp

(100 -> 100) Sneak Tools.esp

(101 -> 101) Sneak Tools Vanilla Hoods.esp

(102 -> 102) Sneak Tools Vanilla Masks.esp

(103 -> 103) dD-No Spinning Death Animation.esp

(104 -> 104) Marriable Serana.esp

(105 -> 105) BecomeKingofSkyrim.esp

(106 -> 106) Alternate Start - Live Another Life.esp

(107 -> 255) BVLT - Human.esp

(108 -> 108) dD - Realistic Ragdoll Force - Realistic.esp

(109 -> 109) SkyRe_Races.esp

(110 -> 110) BarenziahQuestMarkers.esp

(111 -> 111) PLAYER WO.esp

(112 -> 113) ReProccer.esp

(113 -> 114) ETaC - MM Patch.esp

(114 -> 255) DF_T52.esp

(115 -> 255) DF_T52_B.esp

Also the HTD and DF_T52 and DF_T52_B are mods that I removed but they somehow stayed in the skse file(I don't use HiAlgoBoost anymore too).But after playing for a while the game started to CTD again and again(I also checked the temp of cpu and gpu and they are both fine,around 40 degrees C, I have the latest gpu catalysts and lastly I used the nexus mod manager to install some of the mods).If anyone knows why are the CTD's happening and what could be a possible solution, I would appreciated it if you share your knowledge.