5 Ways to Fix ERROR_WOW_ASSERTION 670 (0x29E)

The ERROR_WOW_ASSERTION Windows system error, with code 670 (0x29E), appears due to issues with the Windows on Windows (WOW) subsystem. This usually happens when you try to run a 32-bit application on 64-bit Windows.

The system error is triggered by compatibility issues, corrupted system files, problems with the app installation, and the use of incorrect drivers.

Before you proceed to the solutions, reboot the PC, install any pending software and Windows updates, and verify whether the affected app is compatible with the OS. For most of you, these basic checks will fix Error WOW Assertion!

How can I ERROR_WOW_ASSERTION in Windows?

1. Run the affected app in compatibility mode

1. Right-click on the affected app’s launcher (.exe file), and select Properties.
2. Go to the Compatibility tab, tick the Run this program in compatibility mode for checkbox, and select an older iteration of Windows from the dropdown menu underneath.
3. Click Apply and OK to save the changes, and check whether the app now runs fine.
4. If the system error still appears, pick another older Windows iteration.

2. Repair the corrupted system files

1. Press Windows + S to open Search, type Command Prompt, and click on Run as administrator.
2. Click Yes in the UAC prompt.
3. Paste the following DISM commands individually and hit Enter after each: DISM /Online /Cleanup-Image /CheckHealth DISM /Online /Cleanup-Image /ScanHealth DISM /Online /Cleanup-Image /RestoreHealth
4. Execute this command to run the SFC scan: sfc /scannow
5. Finally, reboot the PC to apply the changes.

When corrupted system files are triggering the ERROR_WOW_ASSERTION 670 (0x29E) WOW Assertion Error issue, running the DISM (Deployment Image Servicing and Management) and SFC (System File Checker) scans will replace all such files with their cached copies.

3. Reinstall the affected app

1. Press Windows + R to open Run, type appwiz.cpl in the text field, and hit Enter.
2. Select the app triggering the system error from the list, and click Uninstall.
3. Follow the on-screen instructions to complete the process and then restart the computer.
4. Finally, download and install a fresh copy of the app from the official website.

If a quick removal doesn’t fix ERROR_WOW_ASSERTION, the app may have left behind files and Registry entries that are still conflicting with the new installation. In this case, I recommend using a top-rated software uninstaller to wipe all traces of the program.

4. Update the drivers

1. Press Windows + X to open the Power User menu, and select Device Manager.
2. Expand the entries here, individually right-click on the devices listed underneath, and select Update driver.
3. Click on Search automatically for drivers and wait for Windows to install the best locally available version.
4. Similarly, update the other drivers and then restart the PC.

In a few cases, instead of an app, an incompatible or buggy driver was triggering the ERROR_WOW_ASSERTION system error. And updating the driver fixed things in no time.

If Windows can’t find a better version, go to the manufacturer’s website and manually install the latest driver. Make sure to verify the driver’s compatibility with the installed architecture of the OS!

5. Perform a system restore

1. Press Windows + S to open Search, type Create a restore point, and click on the relevant result.
2. Click the System Restore button.
3. Select the Choose a different restore point option, if available, and click on Next.
4. Pick the oldest restore point from the list, and click Next.
5. Verify the restore details, click Finish, and confirm the change.

If the previous solutions didn’t work and you can’t identify the underlying cause behind ERROR_WOW_ASSERTION, performing a system restore will revert all recent changes on the PC and take it back to a stable state.

In case this, too, fails, the problem lies with the app (or driver), and you must contact its developers for more help.

Before you leave, learn all the Windows issues and expert fixes, and take the necessary measures to prevent such errors from reappearing!

For any queries or to share more fixes with our readers, drop a comment below.