ERRORBADEXEFORMAT

ERROR_BAD_EXE_FORMAT is a Windows system error code used to indicate that an executable file is not a valid Win32 application. It is defined in the Windows API as ERROR_BAD_EXE_FORMAT and commonly maps to the numeric value 193. When this error occurs, the system or a calling process reports that the image cannot be executed because its format is unrecognized or corrupt.

The error typically appears during process creation or image loading, such as when using CreateProcess, ShellExecute, or LoadLibrary. Windows detects that the target file does not conform to the Portable Executable (PE) format or is otherwise unreadable as a proper executable. In some cases the message shown to users is This is not a valid Win32 application.

Common causes include attempting to run a non-executable file (for example a text document or archive), trying to execute a binary built for a different architecture, or a corrupted or partially downloaded file. On 64-bit Windows, 16-bit Windows executables are not supported, which can also trigger this error if such a file is launched. Misnamed file extensions or faulty third-party launchers can produce the same result.

Troubleshooting steps include verifying the file is indeed an executable and matches the system architecture (32-bit vs 64-bit), re-downloading or reinstalling the program, checking for file corruption, and running a malware scan. If the file is a script or needs a runtime, ensure you are using the correct interpreter or runtime environment. See also Windows error codes and PE format documentation.