Exe Application, first of all, references from a current directory to a subdirectory. And then, system directory. VS6.0 system directory was ..windows/system32. .NET system directory is like the below GAC path.
GAC path
1) C:\Windows\Assembly (for .NET 2.0 ~ 3.5)
2) C:\Windows\Microsoft.NET\assembly (for .NET 4.0)
How to install an assembly into GAC (as Administrator)
1) Drag and Drop
2) Use GacUtil.exe with Visual Studio Command Prompt
gacutil -i [Path][Assembly Name].dll
How to uninstall an assembly from GAC (as Administrator)
gacutil -u [Assembly Name], Version=1.0.0.0, PublickeyToken=7896a3567gh