Each computer where the common language runtime is installed has a machine-wide code cache called the global assembly cache. The global assembly cache stores assemblies specifically designated to be shared by several applications on the computer.  You should share assemblies by installing them into the global assembly cache only when you need to:

Steps:
--- Create a strong name using sn.exe tool
eg: sn -k keyPair.snk
---with in AssemblyInfo.cs add the generated file name.

eg: [assembly: AssemblyKeyFile("abc.snk")]
--- recompile project, then install it to GAC by either
drag & drop it to assembly folder (C:\WINDOWS\assembly OR C:\WINNT\assembly) (shfusion.dll tool)
or
gacutil -i abc.dll