There is not an issue with WMIC for HEC-RAS version 7.0 and newer.  Using the lastest version of HEC-RAS is recommended.

HEC-RAS Version 6.x Issue

The removal of the WMIC utility from Windows 11 is causing older versions of HEC-RAS to not run.  The first part of an example error message from RAS might look like this:

Depending on the version of Windows 11, HEC-RAS may successfully run.  If HEC-RAS does fails, you will see an error message for a SEVERE Fortran runtime failure (Error messages in red text).  Error messages for RasUnsteady.exe will follow and RAS computations will abort. If this happen perform the fix identified below. 

Fix

Follow the instructions provided by Microsoft to install the WMIC utility here (also provided below): Microsoft WMIC fix

Discussion

For older versions of HEC-RAS (6.0, 6.1, 6.2, 6.3.1, 6.4.1, 6.5. and 6.6), HEC-RAS uses a call to "WMIC" (Windows Management Instrumentation Command-line utility) to query the number of computational cores available on the computer.  Starting in 2024, the WMIC utility was disabled in Windows 11 (but available).  In 2026 the WMIC utility was completely removed from Windows 11.  However, Microsoft provides a solution which can be found here: https://support.microsoft.com/en-us/servicing/os/windows/docs/2025/09/windows-management-instrumentation-command-line-wmic-removal-from-windows#bkmk_mitigation. Administrator privilege is required to install this utility.

Steps identified by Microsoft (from the above link) to mitigate the issue are shown below.

  1. Download the wmic_dlc.zip file (link hosted at Microsoft). 

  2. Extract the contents of the ZIP file to a local folder.

  3. Open PowerShell as an administrator. 

  4. Navigate to the extracted wmic_dlc folder.

  5. Run the following command: Set-ExecutionPolicy Bypass -Scope Process

  6. If you're prompted to change the execution policy, select Yes. 

  7. Run the following command: .\install.ps1

  8. Confirm that the script reports: WMIC has been installed successfully.

    1. The installation script copies the WMIC files to the following directory and registers the required WMIC aliases: C:\Windows\System32\wbem.

    2. Retest by running HEC-RAS.

  9. To verify that WMIC is working, run the following command: wmic