RE: Corrupted SPS 2003 Configuration ??

I'm running the prescan tool against a Sharepoint Portal Services 2003
server. I get this error:

Skipping virtual server: . Server state = NeedUpgrade. Most likely
this virtual server is not extended with WSS v2.

This KB says my Configuration is likely corrupted:

http://support.microsoft.com/kb/937291

and suggest I do these steps:

To resolve this issue, follow these steps:
1. Click Start, point to Administrative Tools, and then click
SharePoint Central Administration.
2. On the SharePoint Central Administration Web page, create a new
configuration database.
3. For each virtual server that was extended, click Configure Virtual
Server Settings, and then click Remove Windows SharePoint Services
from Virtual Server. Remember to keep the existing content databases.
4. Use a blank content database to reextend the virtual server.
5. Under Manage Content Databases, remove the blank content database,
and then add the existing content database.
If Prescan.exe cannot upgrade a content database, you may receive the
following error message when you try to upgrade to Windows SharePoint
Services 3.0:

Problem is step #3 does not offer a Remove button or option in SPS
2003.

I've recreated the environment and created a simple site on a VM. I'd
like to POC that I can recreate an sps 2003 site's configuration. Does
anybody have the actual steps?

Also, I'm a bit confused about some terms and concepts.

As far as sps2003 is concerned.

- What's the difference between an sps site a virtual server and a
portal site?
- What does it mean to extend a Virtual Server?
- I noticed options for WSS and SPS in the Central Admin, when do you
use one vs. the other?
- and my original question.. if my configuration is infact corrupted
or bad, and I have all my databases, how can I rebuild the
configuation?

Thank you for any help or information.