Dug Skyrim out the other month and played through vanilla, then this week got around to the modding scene to see what it was all about. "Challenging yet worthwhile" is the overall verdict. Anyway, I've struggled with CTDs for a while. No major load order issues I couldn't overcome; I seemed to be getting memory issues despite all the advice on reallocation of memory, etc. Last night I eventually tracked that down to a conflict between RLO and CoT, which disappeared after disabling RLO. Two solid hours of uninterrupted gameplay before bed and I figure I'm over it. When I shut Skyrim down, it seems my Start Menu has stopped working (Win10, x64). I shut down with a view to looking this morning - which I've duly done. Windows boots up with something along the lines of "Critical Error: Start Menu and Cortana aren't working". Turns out this is a major issue, but a few reboots later all seems fine - a little too much HDD activity at boot, which settles down, but otherwise things work. I fire Skyrim back up with exactly the same mods I used last night, perfectly stable, but now I CTD between the Bethesda logo and the main menu - a clear sign of dodgy mods or load order despite that fact that neither variable there has changed. I'm wondering if something happened with the Cortana cock-up. Anyway, I'm both stumped and utterly wound up and I'm finally admitting defeat, coming to this forum and risking ridicule for some advice! Thank you in advance for anyone prepared to chip in. I've tried to provide as much detail up front as I can but no doubt I've missed some things, so sorry for that. Desperately trying not to be a noob. First things first: Specs i7-3770 @3.5GHz 8GB RAM GTX 660 Ti 2GB Win 10 Active mods in load order (as determined by LOOT via SKSE): Skyrim.esm Update.esm Unofficial Skyrim Patch.esp Dawnguard.esm Unofficial Dawnguard Patch.esp Hearthfires.esm Unofficial Hearthfire Patch.esp Skyrim Project Optimization.esm EFFCore.esp LAnterns of Skyrim Climates of Tamriel Campfire HighResTexturePack1 to 3 Unofficial HighRes Patch When Vampires Attack Guard Dialogue Overhaul Convenient Horses Follower Commentary Overhaul EFFDialogue.esp Skyrim Project Optimization.esp The B-Team UIExtensions.esp Further Dark Dungeons for ENB.esp [part of CoT?] Inigo.esp Run for your Lives Cloaks.esp SMIM-merged No Dragonborn Skyrim Flora Overhaul Legionettes Research Thief HothFollower.esp HothFollower UFO patch.esp Chesko_Frostfall.esp WATER Plants.esp Argonian Access.esp Better Dynamic Snow.esp Moss Rocks.esp WATER DG.esp SkyUI ShootingStars Rainbows Supreme Fog CoT - Dungeons Hazardous CoT - Interiors Cold CoT Weather Patch Supreme Storms CoT version CoT Nights Level 1 Dr_Bandolier.esp CoT-WeatherPatch_NL1.esp CoT-WeatherPatch_SupStorms.esp better_torches.esp Armored Skeletons Apocalypse - the Spell Package.esp Chesko_Wearable Lantern.esp Quick Start [the only change I made between last night's stable session and this morning's farce was to remove this MOD and XCE - now I'm past the start, clearly I don't need it. Can't see this being the issue but I reactivated - still no deal] Not showing are ENB 217 (recommended version by CoT - acknowledge it isn't the latest) run as Injector; ENBoost; CallStabilizer and Memory Blocks Logger in SKSE (latter doesn't log, though, despite all relevant EXEs running as Admin). Key info from various config files: enblocal.ini: Reserved mem 512MB, VSync on, otherwise generally default to what Boris says. SKSE.ini: default heap currently at 1024 (yesterday was 2056, no issues, fiddled since to no avail), scrap at 256. skyrim.ini: iMaxAllocatedMemoryBytes=76800 Probably a few other tweaks but well before I got it stable, nothing I'd expect to break it. Manually set VRAM at around 2G but I think that was superceded by downloading the ENB memory fix for my specific hardware config - I certainly can't find the value in any INI anymore.