problem changing default icon for associated file type

the code im using seems to be working abolutely perfectly, except for 1 small problem, the actual icon isnt changing, ive checked the registry, and the keys are their but the icon isnt changing.. heres all the code in my program associated with the registry..

If My.Computer.Registry.ClassesRoot.GetValue(".PRG") = Nothing Then
My.Computer.Registry.ClassesRoot.CreateSubKey(".PRG").SetValue("", "Pyroguide", Microsoft.Win32.RegistryValueKind.String)
My.Computer.Registry.ClassesRoot.CreateSubKey("Pyroguide\shell\open\command").SetValue("", Application.ExecutablePath & _
" ""%l"" ", Microsoft.Win32.RegistryValueKind.String)

My.Computer.Registry.ClassesRoot.CreateSubKey("Pyroguide\DefaultIcon").SetValue("", My.Computer.FileSystem.SpecialDirectories.MyDocuments & "PyroGuide\Pyroguide.ico", _
Microsoft.Win32.RegistryValueKind.String)

any ideas why it isnt working? i have a suspicion i have the icon part completely wrong (following a tutorial that was hard to follow )