CONCRT140.dll was not found, what it means and how to fix it

CONCRT140.dll is the Concurrency Runtime from Microsoft's Visual C++ 2015-2022 package. Programs that split work across processor cores with the Concurrency Runtime load it at startup, and "was not found" means that runtime is missing or damaged.

The fix, in order

  1. Install the Visual C++ 2015-2022 Redistributable from Microsoft, both vc_redist.x64.exe and vc_redist.x86.exe. The program that failed might be 32-bit even on a 64-bit PC, and it needs its matching flavour. Restart the PC when done.
  2. Already installed? Repair it instead. Settings → Apps → each "Microsoft Visual C++ 2015-2022 Redistributable" → Modify → Repair.
  3. Reinstall or verify the program itself. For Steam games: right-click → Properties → Installed Files → Verify integrity of game files. A damaged program folder can keep failing next to a healthy runtime.
  4. Run Windows Update, then restart. Servicing updates sometimes replace runtime files, and a pending reboot can leave mismatched versions in place.
Do not download CONCRT140.dll by itself. DLL download sites offer single files of random versions, sometimes bundled with installers nobody asked for. The DLL belongs to a matched set installed by Microsoft's package, that package is the fix, and it is free.

If it still happens

Look inside the failing program's folder for its own copy of CONCRT140.dll. Some programs ship a private copy, and if that copy is older or damaged it overrides the healthy system one. Rename it (add .bak) so the program falls back to the system DLL, then relaunch. If only one program fails while others work, that program is damaged, and a clean reinstall is the remaining move.

Common questions

What is the Concurrency Runtime? It is Microsoft's library for parallel programming, used by apps that spread heavy work across several processor cores. It is one component of the Visual C++ 2015-2022 redistributable, so installing that package restores it.

Do I need both the x86 and x64 packages? Yes, on a 64-bit PC. 32-bit programs use the x86 set and 64-bit programs use the x64 set, and you often cannot tell which a program is until it fails.

Related errors

VCRUNTIME140_1.dll missing · MSVCP140.dll missing · api-ms-win-crt-runtime missing

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