Re-Extending Existing Sites
Installing Portal Server removes the association between existing virtual servers and SharePoint. You must re-extend each virtual server before the server and all of the sites it contains will begin working again. To re-extend a virtual server:
From the SharePoint Central Administration page, click Extend or upgrade an existing virtual server → complete list; and then click the name of the server. SharePoint displays the Extend Virtual Server page.
Click Extend and create a content database. SharePoint displays Figure A-4.

Figure A-4. Set the application pool
Select the application pool you wrote down earlier in the "Recording Settings" section, but don't enter database information at this point—you'll re-establish the data connection later. For now, just accept the default content database server, enter a site owner and click OK.
After SharePoint extends the site, click Windows SharePoint Services → Configure Virtual Server Settings → select the site name → Manage content databases. SharePoint displays Figure A-5.

Figure A-5. Removing the default database
Click the database name (STS_servername_n) and select select Remove content database. SharePoint displays a warning. Click OK to close the warning; then click OK again to make the change.
SharePoint returns you ...