All about Global Assembly Cache

· The GAC stores assemblies specifically designated to be shared by several applications on the computer.
· Assemblies deployed in the GAC must have a strong name.
· When an assembly is added to the GAC, integrity checks are performed on all files that make up the assembly. The cache performs these integrity checks to ensure that an assembly has not been tampered with, for example, when a file has changed but the manifest does not reflect the change.

Use a developer tool called the Global Assembly Cache tool (Gacutil.exe), provided by the .NET Framework SDK or Use Windows Explorer to drag assemblies into the cache.