This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Hierdie gesprek is in die argief. Vra asseblief 'n nuwe vraag as jy hulp nodig het.

Can't install FF on newly upgraded Windows 11 - incompatibility error message

  • 2 antwoorde
  • 1 het hierdie probleem
  • 3 views
  • Laaste antwoord deur j.canham-clyne

more options

Bought a new computer that was supposed to come with Windows 11, but came with Windows 10 and right to upgrade. Set up computer, downloaded Firefox, and it ran fine. after a couple of hours, ran the upgrade to Windows 11. Firefox stopped opening. uninstalled then reinstalled Firefox several times, but each time during installation get the following message (image below):

"C:\WINDOWS\SYSTEM32\MSVCP140.DLL is either not designed to run on Windows or it contains an error. Try installing the program again using the original installation media or contact your system administrator or the software vendor for support. Error status 0xc000012f."

Have tried installing with and without defaults, and refreshing instead of reinstalling.

Bought a new computer that was supposed to come with Windows 11, but came with Windows 10 and right to upgrade. Set up computer, downloaded Firefox, and it ran fine. after a couple of hours, ran the upgrade to Windows 11. Firefox stopped opening. uninstalled then reinstalled Firefox several times, but each time during installation get the following message (image below): "C:\WINDOWS\SYSTEM32\MSVCP140.DLL is either not designed to run on Windows or it contains an error. Try installing the program again using the original installation media or contact your system administrator or the software vendor for support. Error status 0xc000012f." Have tried installing with and without defaults, and refreshing instead of reinstalling.
Aangehegde skermkiekies

All Replies (2)

more options

Hmm, that file should come with Windows. Possibly one of your other applications replaced it with an older version? To refresh the Visual C++ DLL files, you can (re)run Microsoft's installer for the VC Runtime files:

(A) Open https://docs.microsoft.com/en-US/cpp/windows/latest-supported-vc-redist?view=msvc-160#visual-studio-2015-2017-2019-and-2022

(B) In the "Visual Studio 2015, 2017, 2019, and 2022" section of the article, download the installer for your system:

  • 64-bit Windows: the "X64" download
  • 32-bit Windows: the "X86" download

(C) Run that installer and restart Windows.

Can Firefox install now?

more options

Five reboots for other updates and a bit of "BIOS Self-Healing" later, yes! Thank you so much!