Should I install both x86 and x64 versions?

Yes, on 64-bit Windows. Many applications are 32-bit and require the x86 version even on 64-bit systems.

What is the WinSxS folder?

WinSxS (Windows Side-by-Side) stores multiple versions of DLLs so different applications can use different versions without conflict.

Windows Side-by-Side Configuration Error — SxS Assembly Failure

Errorapplication

Overview

Windows side-by-side configuration error means an application cannot start because its required assembly (DLL version) is missing or the manifest is corrupted.

Key Details

Full message: 'The application has failed to start because its side-by-side configuration is incorrect'
SxS (Side-by-Side) manages multiple versions of the same DLL on the system
The application manifest specifies exact DLL versions it requires
Usually means a required Visual C++ Redistributable version is missing
Event Viewer > Application log shows the exact assembly name and version that failed

Common Causes

Required Visual C++ Redistributable version not installed
Corrupted C++ Redistributable installation
Application manifest referencing a specific assembly version that does not exist
WinSxS folder corruption preventing assembly binding
Partial application installation missing some dependent assemblies

Steps

1Check Event Viewer > Application log for SideBySide source events — note the assembly name and version
2Install or repair Visual C++ Redistributables: download all versions (2005-2022) from Microsoft
3Reinstall the failing application completely (uninstall first, restart, reinstall)
4Run sfc /scannow to repair corrupted system assemblies
5Run DISM /Online /Cleanup-Image /RestoreHealth to repair the component store