This tool fusion log viewer, coming with Microsoft .Net Framework SDK, is a very useful, but less known. It can display details for failed assembly binds. This information helps you diagnose why the .NET Framework cannot locate an assembly at runtime.
For example, you have written a .Net application and it works on your development machine perfectly. When you deploy it on a testing machine, it throws out exception about assembly binding failure. You know there might be a dependent DLL missing. But how do you figure out which one? use Fuslogvw.exe. It is very possible that in your code you interop some COM components, which have some dependent runtime DLLs are missing on your testing machine. Is it cool?
When you run fuslogvw.exe and it displays nothing, you need to add following flag to the registry.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Fusion
Add a new DWORD key ForceLog, value = 1
You can check out some more details from this blog: Fuslogvw.exe and diagnosing .NET assembly binding issues. Suzanne Cook’s .NET CLR Notes is also a good resource of Common Language Runtime and binding issues.