Register dll to use in SSIS Script Component I've been asked to register an existing dll file so that it can be referenced in an SSIS script component.

I have a dim and distant memory of doing this using gacutil.exe so that was my initial go to. 

However, gacutil.exe is not present on the integration server, presumably because the full version Visual Studio is not installed there, only the Data Tools shell. I have also tried to copy the file into C:/windows/assembly as I read this would work, but nothing happens when I drop the file in it just cancels out.

How can I do this without gacutil.exe? Is there a way or will have to install full VS SDK to do it.
You don't need Visual Studio, you need the Windows SDK. You can use MSDN to find the SDK matching your platform. The assembly has to be strongly named and can only be added to the GAC using the gacutil /i your.dll command or by using a Windows installer package. Prior to .NET 4.0 you could drag and drop the dll into the C:\Windows\Assembly folder but this is now obsolete.