Fix: Fallout: New Vegas Won't Launch on PC (2024 Modding Guide)

Fallout: New Vegas (2010) is notoriously unstable on modern Windows. Follow these systematic fixes.

1. Essential Community Patches (Do First)

• YUP - Yukichigai Unofficial Patch: Fixes 2000+ bugs. Nexus.
• NVSE (New Vegas Script Extender): Required for most mods. NVSE 6.x (xNVSE for GOG/Steam Deck).
• NVAC (New Vegas Anti-Crash): Prevents 90% of CTDs. Nexus.
• NVTF (New Vegas Tick Fix): Fixes stutter, physics, memory. Nexus.
• 4GB Patcher (Steam version): FalloutNV.exe → Large Address Aware. NVSE includes this.

2. Launcher / Settings

• Steam: Properties → General → Force Proton 8/9 (Linux/Deck) or "Run this game in Windows 7/8 compatibility mode" (Windows).
• GOG: Galaxy → Manage Installation → Configure → Compatibility → Win 7.
• INI Tweaks: Documents\My Games\FalloutNV\Fallout.ini / FalloutPrefs.ini:
  • bUseThreadedAI=1
  • iNumHWThreads=2 (or logical cores)
  • iFPSClamp=60
  • bDeferredDelete=0

3. Graphics Drivers & Overlays

• Update GPU drivers (NVIDIA App / AMD Adrenalin).
• Disable Overlays: Steam Overlay, Discord, GeForce Experience, Xbox Game Bar, MSI Afterburner, RivaTuner. They hook D3D9 → crash.

4. Mod Conflicts

• Use MO2 (Mod Organizer 2) or Vortex. Sort with LOOT.
• Disable all mods → test vanilla + YUP + NVSE + NVAC + NVTF. Then enable 5 at a time.
• Common conflict: Project Nevada + WMX + CASM without patches.

5. Windows 10/11 Specific

• Disable "Fullscreen Optimizations" on FalloutNV.exe (Properties → Compatibility).
• Disable "Game Mode" (Settings → Gaming).
• Run as Administrator (sometimes helps).

6. Verify Files

• Steam: Right-click → Properties → Installed Files → Verify Integrity.
• GOG: Galaxy → Manage → Verify / Repair.

Resources

• Viva New Vegas – Gold-standard modding guide.
• The Best of Times (Texture Pack)
• Tale of Two Wastelands – Play FO3 in FNV engine (requires both games).

Follow Viva New Vegas step-by-step. Vanilla FNV on Windows 11 is broken; modded FNV is one of the best gaming experiences ever.