Microsoft said "We've been tracking a small number of customers experiencing issues after installing KB938444 through Windows Update."
"After the reboot at the end of installation we've had reports of Windows SharePoint Services sites and Central Administration being inaccessible with error, "HTTP 404" "Server Error: …" or "Cannot connect to the configuration database". This issue only affects Windows SharePoint Service v3 standalone installations that use Windows Internal Database (wYukon) and doesn't affect SharePoint or user data. If after applying KB938444 you hit one of the errors described above you'll need to run psconfig from an administrator command prompt as detailed below to complete the update: psconfig -cmd upgrade -inplace b2b -wait –force."
More Info: SBS specific steps