Sophos Not Updating
If Sophos Antivirus clients have mysteriously stopped updating on Jan 16th 2009, it may be using an outdated security certificate. A new security certificate was put in place for all clients starting Dec 11th. If the clients haven’t updated since then, further updates will fail until corrective steps are taken.
Run this command:
msiexec.exe /i "c:\program files\sophos\autoupdate\cache\sau\sophos autoupdate.msi" REINSTALLMODE=vdmus REINSTALL=ALL