Install Visual C++ Redistributables

Question

how do i fix missing

api-ms-win-core-winrt-l1-10.dll

Answer 1

Hello Terry Beaudry

Thank you for joining the Q&A forum!

I see you're seeing an error about a missing DLL named api-ms-win-core-winrt-l1-10.dll when launching an application.

If you’re referring to api‑ms‑win‑core‑winrt‑l1‑1‑0.dll, please note that this is a Windows Runtime (WinRT) API set, not a normal DLL that can be installed separately. It’s a core component of the Windows operating system and is not included with Visual C++ Redistributables. As a result, installing VC++ packages will not add this file on unsupported Windows versions.

To better understand the situation, could you please help clarify the following:

• Which Windows version are you using? (Windows 7, 8.1, 10, or 11 including 32‑bit or 64‑bit)
• Which application is showing this error?
• Could you confirm the exact error message text you’re seeing?

If possible, a screenshot would be very helpful. For your privacy and security, please be sure to hide any personal information before sharing.

I look forward to your response so we can determine the most appropriate next steps to resolve the issue.

Yours sincerely.

Answer 2

The DLL name is slightly off. The Windows Runtime core DLL exposed by the API set is api-ms-win-core-winrt-l1-1-0.dll, not api-ms-win-core-winrt-l1-10.dll.

On supported Windows versions, api-ms-win-core-winrt-l1-1-0.dll is part of the OS and provides WinRT core APIs such as:

• RoInitialize
• RoActivateInstance
• RoGetActivationFactory
• RoUninitialize

If an application reports that api-ms-win-core-winrt-l1-1-0.dll (or a mis-typed api-ms-win-core-winrt-l1-10.dll) is missing on a previous Windows version like Windows 7:

1. This API set is not natively available on Windows 7; it was introduced starting with Windows 10 (version 10.0.10240).
2. Installing Visual C++ Redistributables will not add this DLL on Windows 7, because it is an OS-level WinRT API set, not part of the VC++ runtime.
3. The only reliable fix is to run the application on a supported Windows version that includes WinRT (Windows 10 or later). On those systems the DLL is present as part of the OS and should not be manually installed.
4. If the error appears on Windows 10 or later, it usually indicates a damaged or incompatible application installation rather than a missing OS DLL. In that case, reinstalling or downgrading the application to a version that supports the current OS is required.

For older systems like Windows 7 where this API set does not exist, the practical workaround is to use an application version that does not depend on WinRT APIs. For example, when Adobe Reader fails on Windows 7 with a missing WinRT DLL, using an older Reader version that supports Windows 7 and disabling its automatic updates avoids the error.

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References:

• APIs present on all Windows devices (grouped by module)
• Missing api-ms-win-core-winrt-l1-1-0.dll - Microsoft Q&A