Error 126 in the Windows operating system signals a problem with the loading of a dynamic link library (DLL). DLL files are used in Windows to re-use common functionality or to make the executable file smaller. DLL files can be loaded during the startup of the application (EXE) or at runtime, when the functionality is needed.
When Windows or any program tries to load a DLL and it fails, system error 126 may occur. As a result, error 126 can happen with almost any program that is using DLL files, like games, DirectX, databases, etc.
Top Causes for Windows Error 126
Even though the basic problem with error 126 is the failure to load the DLL file, there can be a number of causes for this error. The first possibility is that the DLL file is really missing. In itself this is a rare cause, as DLL files are not normally in a location where they would be accidentally deleted.
The second possibility is that the DLL file is corrupt. When Windows tries to load the DLL file, the file needs to adhere to a specific format, or the loading will fail. Possible causes for file corruption are disk errors, viruses and malware.
The third possible option is that the DLL file is where it should be and the file is not corrupt, but the reference to the DLL file is corrupt. This would mean a problem with the Windows registry. All DLL files need to be registered in Windows, and the details of these DLLs are recorded in the Windows registry. So if the details are corrupt or missing, the DLL will not load as well.
Fixing DLL Error 126
Considering the causes for Windows error 126, there are a number of steps you can take to repair this error.
• Run a disk check to check the hard disk for any errors that may be responsible for file corruption.
• If the DLL file is a Windows system file, you may be able to repair the DLL file by running “SFC SCANNOW” at the command prompt. This will require administrator access rights, so use a user account with admin level rights. The SFC command checks the Windows system files and tries to repair any errors found. When an error is found, you may be required to provide the original Windows CD to retrieve the original files.
You can also try to manually restore the copy of a Windows DLL file from the Windows setup CD using the “expand” command, but in general the SFC command is easier and more reliable.
• Update your antivirus software and run a full system scan. This will take some time, but it will ensure that there is no virus on your hard disk that could be responsible for the DLL file corruption.
• Reinstall the software in which the error is occurring. If a game is experiencing Windows error 126, try reinstalling the game. If you get Windows error 126 for a DirectX dll, like d3dx9_36.dll, try reinstalling DirectX 9.
Reinstalling the software will generally restore the missing or corrupt DLL file and also reregister it in the Windows registry, in many cases fixing Windows error 126. If reinstalling does not work the first time, uninstall the software first, reboot and then reinstall the software.