More On Network Settings:

The second required setting is done with the “Users and Groups” Control Panel. Here you need to turn on “Link To Programs.”

You can turn this on for Guest if you don’t need to restrict the access. If you need to set up a password for this, you can create a new user, and set a password for this option.

That completes the setup for diagnosing a machine over the network. You may want to look at the help topic “Diagnosing Via Network” for more information.