Errors related to ext-ms-win-ntuser-windowclass-l1-1-1.dll can arise for a few different different reasons. For instance, a faulty application, ext-ms-win-ntuser-windowclass-l1-1-1.dll has been deleted or misplaced, corrupted by malicious software present on your PC or a damaged Windows registry.
The most commonly occurring error messages are:
- The program can't start because ext-ms-win-ntuser-windowclass-l1-1-1.dll is missing from your computer. Try reinstalling the program to fix this problem.
- There was a problem starting ext-ms-win-ntuser-windowclass-l1-1-1.dll. The specified module could not be found.
- Error loading ext-ms-win-ntuser-windowclass-l1-1-1.dll. The specified module could not be found.
- The code execution cannot proceed because ext-ms-win-ntuser-windowclass-l1-1-1.dll was not found. Reinstalling the program may fix this problem.
- ext-ms-win-ntuser-windowclass-l1-1-1.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 vender for support.
In the vast majority of cases, the solution is to properly reinstall ext-ms-win-ntuser-windowclass-l1-1-1.dll on your PC, to the Windows system folder. Alternatively, some programs, notably PC games, require that the DLL file is placed in the game/application installation folder.
For detailed installation instructions, see our FAQ.