Recently, I have just setup my new company laptop to run Windows 2008 as a desktop and reinstalling SharePoint in Hyper-V.  Upon completion of the installation and while accessing the Shared Services Provider, I was prompted continuously with authentication prompt, even I have entered the correct user and password.  Subsequently, I am just presented with a blank page.

There is a KB article at http://support.microsoft.com/kb/896861 that describes the same scenario.

This is more of a note to myself to remember to set the DisableLoopbackCheck in the registry:

Steps:

1. Open your registry editor by going to Start –> Run and enter regedit and click OK.
2. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa in the registry editor.
3. Right-click Lsa, click on New and select DWORD value.
4. Enter DisableLoopbackCheck and press Enter.
5. Right-click DisableloopbackCheck and select Modify.
6. In the Value data box, enter 1 and click OK.
7. Restart your server.

I would recommend that you do this on at least the Central Administration server, if not all WFE servers.