Sophos Endpoint Security and Control: Deployment of Sophos Client Firewall fails after removing Symantec SEP 11 on Windows 2000

Issue
When removing Symantec Enterprise Protection 11 using the 'Protect computers' wizard with 'Remove third-party software' selected in Enterprise Console, version 3.1 and above, the following error message is displayed in Enterprise Console; neither Sophos Anti-Virus nor Sophos Client Firewall is installed:

'Failed to install Sophos Client Firewall: The msi failed'

Sophos product and version
Sophos Endpoint Security and Control, version 8.0 and above
Sophos Enterprise Console, version 3.1 and above

Operating system
Windows 2000+

What to do

1. Reboot the affected computers.
2. In Enterprise Console, in the list of computers, select the computers that failed to install the Sophos Client Firewall.
3. Click 'Protect computers' to redeploy the wizard and install Sophos Anti-Virus and Sophos Client Firewall.

Technical Information
This error occurs when attempting to remove most versions of the Symantec Enterprise Protection 11 product suite. However, if the product suite has been updated with the 11.0.1000.1375 Symantec patch, you can avoid this error by ensuring that the computer has rebooted before attempting to remove Symantec and replace it with Sophos products.