When attempting to run an upgrade using Symantec Installation Manager you may receive an error message stating a failure to validate anagersetup.exe.
User Access Control (UAC)
In this particular case, User Access Control (UAC), was causing this problem. Disabling User Access Control resolved the issue.
It is always a good idea to disable UAC when an install, upgrade, or point-fix implementation is planned. In addition, it's also a good idea to temporarily disable anti-virus real-time scanning for the duration of the planned install, upgrade, and point fix implementation.