Computer wasn’t taking the application of Service Pack 2 for Windows XP very well. After application and reboot, system’s Network Connections disappeared and the Firewall reported corruption, but couldn’t be repaired.
-“Systems that have changed the default Access Control List permissions on the %windir%\registration directory may experience various problems after you install the Microsoft Security Bulletin MS05-051 for COM+ and MS DTC”
System had errors consistent with those described in the above article. After applying proscribed Resolution, system appears to be functioning normally.