Please realise that on this forum it's mainly other users who reply to you, not TGC employees (remark: there is a form in the web site menu to send mail directly to them if you very much want to). If other users haven't come across your problem yet and don't know the solution, then there will be no reply. Second, it's very difficult to troubleshoot an installation problem without sitting in front of the computer in question.
To be more helpful, try this: Open the wizard files in a text editor. These are the files with the "vsz" extension that you have in the Visual Studio 2008\Wizards folder. There should be three of them for the three wizards. They all contain a path. For example:
Param="ABSOLUTE_PATH = C:\Users\YourUserName\My Documents\Visual Studio 2008\Dark GDK\Dark GDK - Game\Dark GDK - Game"
Check if that directory path really exists, and if there is a Visual Studio project inside it. (Files with sln extension and further subdirectories with vcproj files inside them.) It is possible that the files were copied to a different place then the path set in the wizard files. (For example, on my computer the installer created a second copy of the My Documents directory, because my Windows is not English... weird but as long as it works, I don't care about correcting it.)
If the path does not fit the location where the project files are, then either copy the project files to the place where the path points to, or correct the path in the "vsz" file with text editor. For more guidance see this post:
http://forum.thegamecreators.com/?m=forum_view&t=118371&b=22&msg=1793748#m1793748
As a final alternative, you can try using Dark GDK without wizards. Set the location of the Dark GDK (and the DirectX SDK) header files as "additional include directories" for the C++ code generation, and the location of the library files as "additional library directiories" for the linker. These can be set in the project options, but the directories can also be set in the global Visual Studio options under "VC++ directores".