Installation and configuration issues can occur when User Account Control (UAC) is enabled on a client's system. 

User Account Control (UAC) is an integral part of the Microsoft Windows security model. It allows administrative users to log on to Windows with a "split token" - a limited user token is provided to log in. When necessary, the user is prompted to provide an administrative token to perform tasks requiring elevated privileges set by the application developers and/or the operating system. 

Disabling UAC should not be necessary when installing or administering a Symantec product. However, elevated privileges may be necessary to launch certain Symantec applications from the GUI or an elevated command prompt.

Tip: Want to test if UAC is enabled on a client machine? Download Symantec SymHelp® onto the client machine.  During installation, an alert will indicate if UAC is enabled.

Additional information on Windows User Account Control (UAC): 

• User Account Control Step-by-Step Guide
• UAC Group Policy Settings and Registry Key Settings