Applies to Windows Vista and Windows 7
Error Message: The installation of Sophos Anti-Virus has failed (error 0x80041f09)
The first thing to check is whether the User Access Control is enabled; kindly disable and try re-installing Sophos
Control Panel - Users Accounts - Change User Account Control Settings
In most cases; the above step should get you through; if not look no further beyond the below link
http://www.sophos.com/en-us/support/knowledgebase/1462/8450/8550/13418.aspx
