Sharepoint Upgrade Fails During First Time Sql 2005 Workgroup Ed. Setup

I have installed SBS 2003 Premium with Exchange 2003 SP1 and now I want to install SQL server 2005 workgroup edition.

Heres what I noticed during setup, following the steps of the Server 2005 Workgroup Edition instructions, starting with Upgrading the Sharepoint instance of WMSDE.

Preparing the http://companyweb website:
Step 4. I should make a backup of the data directory within program filesMicrosoft SQL ServerMSSQL$SHAREPOINT directory. However there is no data-directory there, so nothing to backup there. This is probably the reason for all the rest of the issues, however what does it mean, why is there no such directory present? I checked before doing the sql install that by going to http://companyweb I did indeed land on the sharepoint internal website.

Rest goes all normal, until :
Attaching the databasefiles to the new SHAREPOINT instance of SQL server 2005.

Step 4.: go to MSSQL$SHAREPOINTdata. Not only is there no such subdirectory now, the whole MSSQL$SHAREPOINT directory has in fact now disappeared. So steps 4 till 6 cannot be performed now.

Then further to
Enable full text search in Windows Sharepoint services
Step 2. Remark: I get the error message as described there, however the solution would be to start the SQL server (Shareoint service. However that service is up and running

Furthermore when I go to http://companyweb now, I also get the errormessage indicating no connection can be established with the configuration database.

When I check for services, I find that the whole MSSQL$SHAREPOINT service has disappeared from the list of services.