How to troubleshoot api-ms-win-core-processthreads-l1-1-1.dll errors

A api-ms-win-core-processthreads-l1-1-1.dll-specific sequence based on ApiSet Stub DLL and its supported delivery through Microsoft® Windows® Operating System.

1

Identify the requesting application and package identity

Record the affected program, exact api-ms-win-core-processthreads-l1-1-1.dll message, Windows version, and whether the app is 32-bit or 64-bit.

2

Repair the owning application or Windows package

Open Settings > Windows Update, select Check for updates, install all applicable updates, and restart. If the Windows component remains damaged, open Command Prompt as administrator, run DISM RestoreHealth, wait for completion, and then run SFC.

3

Retest the original application operation

Restart Windows after the supported repair, launch the same affected program, and repeat the action that produced the original message. If api-ms-win-core-processthreads-l1-1-1.dll still fails, record the new exact error and stop before making unrelated system changes.

Safety warning: Do not copy or register api-ms-win-core-processthreads-l1-1-1.dll in isolation. No. Repair api-ms-win-core-processthreads-l1-1-1.dll through Windows Update or supported Windows servicing so dependencies and servicing metadata remain compatible.

Windows Repair Intelligence™ DLL Report

api-ms-win-core-processthreads-l1-1-1.dll

ApiSet Stub DLL

Home / DLL Library / ApiSet Stub DLL / api-ms-win-core-processthreads-l1-1-1.dll

api-ms-win-core-processthreads-l1-1-1.dll is a locally observed ApiSet Stub DLL associated with Microsoft® Windows® Operating System. WinLab recorded 12 distinct signed specimens so version, x64/x86 architecture, size, publisher, signature, and SHA-256 can be compared before choosing a supported repair path.

PublisherMicrosoftArchitecturesx64 / x86Source classWindows componentReviewedSeptember 1, 2026

What is api-ms-win-core-processthreads-l1-1-1.dll?

api-ms-win-core-processthreads-l1-1-1.dll is identified in the observed specimens as ApiSet Stub DLL, published by Microsoft Corporation for Microsoft® Windows® Operating System. Its identity depends on the complete package, build, and architecture—not its filename alone.

Common Error Messages

  • "api-ms-win-core-processthreads-l1-1-1.dll was not found"
  • "The code execution cannot proceed because api-ms-win-core-processthreads-l1-1-1.dll is missing"
  • "The specified module api-ms-win-core-processthreads-l1-1-1.dll could not be found"

Common Causes

  • The package that owns api-ms-win-core-processthreads-l1-1-1.dll is incomplete or damaged
  • api-ms-win-core-processthreads-l1-1-1.dll does not match the affected program's x64/x86 architecture or package build
  • Security software quarantined the ApiSet Stub DLL component
  • An application or Windows update left mismatched api-ms-win-core-processthreads-l1-1-1.dll dependencies
AI

Smart diagnostic checkpoint

AI-assisted · grounded in this report's reviewed evidence
Package ownerMicrosoft® Windows® Operating System

Serviced through Windows—not a loose DLL download.

Best first routeRepair the owning application or Windows package

Match the affected program and x64 / x86 architecture before repairing.

System repair?Applicable after evidence checks

Use DISM, then SFC, only after updating Windows and checking the affected component.

Stop and reassessIf the exact message changes

Capture the new wording and affected program. Do not continue repeating unrelated repairs.

Fix the program that reports api-ms-win-core-processthreads-l1-1-1.dll

This decision path is specific to ApiSet Stub DLL. api-ms-win-core-processthreads-l1-1-1.dll is a locally observed ApiSet Stub DLL associated with Microsoft® Windows® Operating System. WinLab recorded 12 distinct signed specimens so version, x64/x86 architecture, size, publisher, signature, and SHA-256 can be compared before choosing a supported repair path.

1

Preserve evidence from the api-ms-win-core-processthreads-l1-1-1.dll dialog

Note the affected program, the action that triggered the failure, and what changed immediately beforehand. Save open work and close that program normally; use Task Manager only if it is frozen or the supported repair tool says it is still running.

Record the exact message “api-ms-win-core-processthreads-l1-1-1.dll was not found” before closing it.
2

Decide whether the failure is app-local or Windows-wide

If one program alone reports api-ms-win-core-processthreads-l1-1-1.dll, repair that program first. If unrelated programs or Windows features fail too, check Windows Update history and service the complete Microsoft® Windows® Operating System rather than copying one API-set or runtime file.

Protected location to verify after servicing: C:\Windows\System32\downlevel\api-ms-win-core-processthreads-l1-1-1.dll.
3

Repair the owning application or Windows package

Record the exact program and message that requests api-ms-win-core-processthreads-l1-1-1.dll. Then compare its version, architecture, Microsoft Corporation signature, size, and SHA-256 with the verified rows. Use Repair or Change only when Windows or the official installer actually offers that option.

Use WinLab locally observed signed-file inventory as the evidence route; do not download api-ms-win-core-processthreads-l1-1-1.dll separately.
4

Retest the original application operation

Apply supported Windows servicing for Microsoft® Windows® Operating System. Launch the same program and repeat the original action. If the wording changes, capture the new error and reassess instead of repeating unrelated repairs.

Validation target: The package that owns api-ms-win-core-processthreads-l1-1-1.dll is incomplete or damaged.

Page-specific safety boundary: api-ms-win-core-processthreads-l1-1-1.dll is serviced as Microsoft® Windows® Operating System. Resetting an application may erase its data but cannot replace an unsupported Windows API or hardware feature.

Verified file intelligence

Official-source grounded

Versions, hashes, and signatures can vary by supported package release. This report does not invent a universal "latest file" value. Confirm package selection against WinLab locally observed signed-file inventory (WinLab collector).

Verified api-ms-win-core-processthreads-l1-1-1.dll file versions

12 observed builds

Distinct locally observed specimens are deduplicated by version, architecture, and SHA-256. A signature result identifies the inspected file; it is not a recommendation to copy a loose DLL into Windows.

VersionArchitectureFile sizeLanguageSignature
10.0.10240.16384 (th1.150709-1700)x6429.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-256a24390c33552722ad34310c585cef24521f1442df67d0728baee8418fb2d0a69
10.0.10240.16384 (th1.150709-1700)x6429.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-256a32bd94844e3f68c96c68b59d6d32faeea91b5f249de6e856cf8cfeda318aade
10.0.10240.16384 (th1.150709-1700)x6429.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-256b157809395343cbad4a3319ff7c412dbb0f497c524e21100e8bea114a2436e22
10.0.10240.16384 (th1.150709-1700)x6429.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-256dd43895c56e6b59a03316610470db9b9d45f41c8a15a0a69f6ae092a315c81db
10.0.10240.16384 (th1.150709-1700)x6429.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-256e5e33d230be380ce30a450875027a763e9d61c7e783a2e0092a3921fb9890336
10.0.10240.16384 (th1.150709-1700)x8629.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-25603526f1a5c95733a4789829a36fc609724fd3dc71d5679910a4a1146b00355bd
10.0.10240.16384 (th1.150709-1700)x8629.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-2563a23d54e77aecd6bca6b48251ca350eca6b70cec803e91421040c75c210b158d
10.0.10240.16384 (th1.150709-1700)x8629.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-2565fbf4023ba31ef65bf098e07f6b6848f5e508fcdd6940d2f606547c595cbfeef
10.0.10240.16384 (th1.150709-1700)x8629.1 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-2567ef96adc96520e3d6c100b85c75d594d37e188abeb3ff565931d6ec7e919f710
10.0.22621.2428 (WinBuild.160101.0800)x6422.4 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-2566f505c660cd78836fc8128bef43082fc9ce8f9a93cc424af039b92daace8daa1
10.0.26100.1 (WinBuild.160101.0800)x6421.4 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-256dc309ed7f947095a17c24bebc756e2db66e3270f588849c4dfbf4e965f5cd1ae
10.0.26100.1 (WinBuild.160101.0800)x8612.9 KBEnglish (United States)Valid
PublisherMicrosoft CorporationDescription / observed sourceApiSet Stub DLL · Installed applicationSHA-256beecec90edb5d8f855f0938a8b9d0f3bda5f5a052dc9c651366ef5178ee50c3e

Evidence method: file metadata read from the observed specimen, SHA-256 calculated by WinLab, and digital-signature status checked through Windows Authenticode. Observed 2026-08-31.

Frequently Asked Questions

AI-assisted / evidence reviewed

How we use AI: AI helps draft clear answers, but every published technical claim must be tied to an approved source, pass safety checks, and receive editorial review. It may not invent versions, hashes, signatures, download links, or success rates.

What is api-ms-win-core-processthreads-l1-1-1.dll?

api-ms-win-core-processthreads-l1-1-1.dll is identified in the observed specimens as ApiSet Stub DLL, published by Microsoft Corporation for Microsoft® Windows® Operating System. Its identity depends on the complete package, build, and architecture—not its filename alone.

Which api-ms-win-core-processthreads-l1-1-1.dll version is correct?

There is no universal loose-file version. Match the affected program, package build, x64/x86 architecture, Microsoft or publisher signature, file size, and SHA-256 to the verified api-ms-win-core-processthreads-l1-1-1.dll evidence.

Should I download api-ms-win-core-processthreads-l1-1-1.dll by itself?

No. Repair api-ms-win-core-processthreads-l1-1-1.dll through Windows Update or supported Windows servicing so dependencies and servicing metadata remain compatible.