You receive an HTTP 404 error message when you browse the SharePoint site collections after a hotfix package or a public update for Windows SharePoint Services 3.0 is applied

If the "official" procedure below does'nt work, please check if the Named Pipe protocol is enabled in your SQL Server Configuration Manager.

Click Start, click Run, type cmd, and then click OK.

Locate the \"Program Files\\Common Files\\Microsoft Shared\\Web server extensions\\12\\BIN\" folder.

At the command prompt, type the following commands, and then press ENTER after each command:

stsadm -o provisionservice -action stop -servicetype spwebservice -servicename ""

stsadm -o provisionservice -action start -servicetype spwebservice -servicename ""

After the SPWebService service is started, type the following command at the command prompt, and then press ENTER:

psconfig -cmd upgrade -inplace b2b -wait -force