Yes, first make sure you download WinSCP Portable executables pack 5.0.7 and WinSCP .NET Assembly/COM library pack 5.0.7.
Extract all to the same directory.
No registration (GAC nor COM) is needed.
In Visual studio pick Add Reference and browse for the winscp.dll from WinSCP .NET Assembly/COM library pack.

dont forget that the automation pack is 5.0.7 beta, so dont go mixing it with other versions.

still it should have been added as a reference without a problem. though you would have encountered the version problems later.

only did point 1 and 2 myself and created a project in visual studio 2010 and added the winscp.dll as reference and put the winscp.exe in the release/debug directory.

1: download the automation pack. for .net dll
2: download the Executables for Winscp
3: Copy the Directory WinScp438 into a directory. and also the dll into the same directory and install by doing the follwing command line
4: c:\Program Files\Microsoft Visual Studio 9.0\VC>gacutil /i "c:\Program Files\winscp438\WinSCP.dll"
5: c:\Program Files\Microsoft Visual Studio 9.0\VC> "c:\Program Files\winscp438\WinSCP.dll" /codebase /tlb
6: Create a new project Visual studio 2008
7: GAC version is not shown in the Addrefference, so go to browse and locate the winscp.dll, Still wont accetp there is the following error message. what am i doing wrong.

Error "Warning 1 The referenced component 'WinSCP' could not be found. "
using WinScp; "Cannot resolve symbol Winscp".