Quartus did not start

I have included all my screenshots here. Could you also include the relevant screenshots you have so that I can compare and provide internal feedback?

Please also include information about your antivirus and firewall.

Hi everybody,

I’m experiencing the same issue here. The machine is running multiple versions of Quartus Prime Pro (23.4, 24.1, 24.3, and 25.3), all patched in January due to the infamous date/time issue.

The system is running Windows 11 25H2, and no software or driver changes have been made in the last 30 days. Windows localization is set to Italian.

The Linux version of Quartus Pro works fine, fortunately.

About two years ago, I had a similar problem and opened a post here: https://community.altera.com/discussions/nios-system/niosv-shell-and-riscfree-dont-start---application-error/297403

At that time, however, I was able to solve the issue simply by rebooting the PC, also because the team was not able to reproduce the error. I've tried to reinstall Visual C++ redistributables but with no luck.

is anyone else using Sophos Endpoint?

We understand how disruptive the “The application was unable to start correctly (0xc0000142)” error can be.

We have attempted to replicate the problem in our in-house environment, but so far we have been unable to duplicate the issue. As a result, your assistance with the following debugging steps is essential to help us narrow down the root cause and resolve this matter as efficiently as possible.

Debugging Steps:

Reregister All DLL Files

• Open Command Prompt as Administrator (search for cmd, right-click, select "Run as administrator").
• Run the following command and press Enter:for %i in (%windir%\system32\*.dll) do regsvr32.exe /s %i
• Then run:for %i in (%windir%\system32\*.ocx) do regsvr32.exe /s %i
• Close Command Prompt.

Set Correct System Locale

• Press Windows + R, enter intl.cpl, and click OK.
• In the Administrative tab, click Change system locale... and select the English region (e.g., English (United States)).
• Click OK and restart your computer.

Run Quartus as Administrator

• Right-click the Quartus icon, select Properties.
• Under the Compatibility tab, check Run this program as an administrator.
• Click Apply and OK.

Reset LoadAppInit_DLLs Registry Value

• Press Windows + R, type regedit, and press OK.
• Navigate to:
  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
• Double-click LoadAppInit_DLLs and set the value to 0.
• Click OK and restart your PC.

Install Latest Microsoft C++, .NET Framework, and DirectX

• Download and install the latest versions:
  • Microsoft Visual C++ Redistributables
  • .NET Framework
  • DirectX End-User Runtime Web Installer
• Restart your PC.

Use Process Monitor (Advanced)

• Download Process Monitor.
• Run Procmon.exe, start Quartus, and look for any “NAME NOT FOUND” or “PATH NOT FOUND” errors indicating missing DLLs.

Update Graphics Drivers

• Visit your graphics card vendor’s website (e.g., NVIDIA Driver Downloads), download and install the latest driver for your GPU, and restart your system.

Next Steps:

Please proceed through these steps, restarting your system after each major change. If the error persists after completing these steps, kindly let us know which steps you have tried and any observations or error messages you encounter. This will help us further isolate the issue and recommend the next course of action.

We greatly appreciate your cooperation and patience

It seems Sophos isn't the problem. Our administrator has partially disabled Sophos's access and Quartus didn't start.

We have followed the debugging steps suggested by KennyT and the process monitor is showing numerous issues with “NAME NOT FOUND”.

The attached log is from last week before trying any of the new steps. There are plenty of "NAME NOT FOUND" but for many if not all of those instances a DLL is eventually loaded.  See the related list of loaded DLLs in my earlier post.

Turning off Sophos allows me to run QuartusPro, same as others have noted.

However I still get 0xc0000142 DLL issues when trying to run a few  utilites: quartus_sign, quartus_worker, and quartus_encrypt. There may be others.

Running with something as simple as -h command line option fails.