If we have two version of same assembly in GAC how do we make a choice ?

OK first let’s try to understand what the interviewer is talking about. Let’s say you have made an application and its using a DLL which is present in GAC. Now for some reason you make second version of the same DLL and put it in GAC. Now which DLL does the application refer? Ok by default it always uses the version by which you have compiled you application in IDE. But you want that it should actually use the older version.

So first we answer in short. You need to specify “bindingRedirect” in your config file. For instance in the below case “ClassLibraryVersion” has two versions “1.1.1830.10493” and “1.0.1830.10461” from

Is versioning applicable to private assemblies?

Versioning concept is only applicable to global assembly cache (GAC) as private assembly lie in their individual folders.

Where is version information stored of an assembly ?

Version information is stored in assembly in manifest.