Unable to un-install Symantec Endpoint Protection Anti-virus

I am trying to assist my Dad with a problem that recently occurred.  He has a 32 BIT operating system running VISTA with service pack 2.  His anti-virus program is Symantec Endpoint Protection that was installed 4/20/2008 with no issues until a couple of weeks ago.  He received messages that the Live Update was not functioning.  I hooked into his computer remotely and tried to repair it with the Symantec installation disk and it hangs up with a message of “Gathering Required Information” and never finishes.  We get this same message if I try to remove it, install it again, or use Clean Wipe to remove it.  I think it might have something to do with the Windows Installer but could us some advice before I go any further.

 

Any help would be appreciated,

Cheers from Philip