(Like many of my technology postings, this is really here for my own notes on problems I run into, the solutions I try and what works when. They are updated as I learn.)
Make sure that an update is not currently being performed. You can check this by right-clicking the Sophos shield in the system tray of the taskbar and ensuring 'View updating status' is grayed out and cannot be selected.
Open Windows services (Start | Run | Type: services.msc | Press return), right-click on the 'Sophos AutoUpdate Service' and select 'Stop'1.
Remove the Sophos components in the list below in order. If you cannot find one or more components listed below it may not be installed and you can move on to the next item. You do not have to restart the computer until you have finished the list. I use Revo Uninstall Portable, in fact I went ahead and purchased the Pro version. Worth it.
Sophos Patch Agent
Sophos Compliance Agent (NAC)
Sophos Network Threat Protection
Sophos System Protection
Sophos Client Firewall (SCF)
Sophos Anti-Virus (SAV)
Sophos Remote Management System (RMS)
Sophos Management Communication System (MCS)
Sophos AutoUpdate (SAU)
Sophos SafeGuard components
Sophos Endpoint Defense
6.Restart the computer.