This is how to properly disable loopback on your SharePoint Servers
Warning** If you do not know what you are doing here than make sure you have some proper supervision before attempting this. ***
Run > type regedit. Then go to the following location
Create a new dword called DisableLoopBack and set the value to 1
Now go to the following location
Create a New Dword: DisableStrictNameChecking
Finally you can end it by creating NEW Multi-String Value: BackConnectionHostNames at this location:
in the multistring text box area, fill out all of your web application site names that you will be testing from the server
