Server App Unavailable Error

I have a web service that I can access from a client machine as long as that web service is on the machine I delevoped it on. I created a virtual directory on our server's (Small Business Server 2000) internet information server and put all of the web service's files in the inetpub/wwwroot folder. However, when I try to access the web service while it's on the server I get an error that says that the server application is unavailable.

The error says to reference the system logs for a detailed description of the failure. When looking at the Event Viewer on the server the following error shows up:

"aspnet_wp.exe could not be launched because the username and/or password supplied in the processModel section of the config file are invalid"

I'm new to asp.net. Does anyone have any insight as to why this is happening?

Thanks in advance.http://support.microsoft.com/default.aspx?scid=kb;en-us;q315158&

CAUSE
By default, ASP.NET runs its worker process (Aspnet_wp.exe) with a weak account (the local machine account, which is named ASPNET) to provide a more secure environment. On a domain controller or on a backup domain controller, all user accounts are domain accounts and are not local machine accounts. Therefore, Aspnet_wp.exe fails to start because it cannot find a local account named "localmachinename\ASPNET". To provide a valid user account on the domain controller, you must specify an explicit account in the <processModel> section of the Machine.config file, or you must use the SYSTEM account.

etc.