Paths in your code are invalid.
The wrong string is:
startInfo.Arguments = @"C:\Program Files (x86)\VisualSVN Server\bin\svnadmin dump E:\Repositories\Test > E:\AFS\AFS.Schedule.VisualSVN\TestFolder\Dest\Test\NewTest.dump";
The correct string is:
startInfo.Arguments = @""C:\Program Files (x86)\VisualSVN Server\bin\svnadmin.exe" dump E:\Repositories\Test > E:\AFS\AFS.Schedule.VisualSVN\TestFolder\Dest\Test\NewTest.dump";
Note the missing .exe
and quotation.