404 Error When Opening HTTP://companyweb

Just encountered the problem while working with a client.  If you see this in your dealings this may help you out.

To resolve this problem, follow these steps to restart the SharePoint services and to complete upgrade:

1. Click Start, click Run, type cmd, and then click OK.
2. Locate the following folder:
   %COMMONPROGRAMFILES%\Microsoft Shared\Web server extensions\12\BIN
3. At a command prompt, type the following command, and then press ENTER:
   psconfig -cmd upgrade -inplace b2b -wait –force

If the upgrade does not complete succussfully, type the following commands at the command prompt, and press ENTER after each command:
net stop MSSQL$MICROSOFT##SSEE
net start MSSQL$MICROSOFT##SSEE
psconfig -cmd upgrade -inplace b2b -wait -force

This should resolve the problem for you.