Question : Cannot log in to CompanyWeb or Sharepoint Central Administration

I have a new install of SBS2003.  I am logged into the server as the Administrator.  Each time I try to open Sharepoint Central Administration or CompanyWeb, I get a login screen which will not accept my administrator password, or other user credentials.  After 3 tries I get an error page.  I have followed the KB 829114 for un-installing Sharepoint 2.0, and then re-installing, but still have the same problem.
All Windows updates have been installed.
I have 2 NIC connections, and can access internet fine from server and client computers.
Thanks for your help.

Answer : Cannot log in to CompanyWeb or Sharepoint Central Administration

I  have a single server running SBS 2003, two client computers attached at this point for testing purposes before adding the remaining ones.  Both client computers were set up using ConnectComputer, and connected successfully.
 I am logged in to the server as the administrator with the Builtin Administrator account.  Prior to posting this question, I had done the following:  
Checked the Permissions under IIS/Web sites/Companyweb and Sharepoint as well as IIS and Sharepoint Security permissions all show the Administrator account with full privileges, as is the user account used from client computer that is part of the Administrators group.

I have used the format Username, server\username, and username@server, all wich only return the login screen.
I have re-run CEICW.
companyweb has been added to Intranet trusted sites.
So I think I had already covered the items suggested.

I do note that under Web Sites in IIS there are only 3 default web sites, not 4 as described by Jeff in his postings here on EE:
http://www.experts-exchange.com/Software/Server_Software/Web_Servers/Microsoft_IIS/Q_22623454.html

.  The Microsoft Sharepoint Administration one is missing.  Default, Com;anyWeb, and Sharepoint administration are listed.