When installing Sophos Anti-Virus for Windows 2000+ on a Windows 2000, XP or 2003 computer, the following error is displayed, and installation fails:
Installation failed: 80090016
Could not start installation program on the computer: Keyset does not exist.
What to do
This is a known Microsoft issue. Scheduled tasks cannot run correctly as the Protected Storage service has not been started. This can be because of a group policy that has been applied to the network. The recommend Microsoft workaround for this issue can be found in Microsoft Knowledge Base Article 246183.