1) First Download the attached file, it is an autoit exe file I have created to answer the EULA McAfee throws at you.
2) Next you'll want to find the file VSOVER.INI, scroll to the bottom of it and you should see:
CODE
[InstallConfig]
Welcome="-1"
SilentInstall="0"
ProductName="VirusScan Professional"
RemoveSetupFiles="0"
CDRomBuild="1"
MISInstall="-1"
CreateUninstShortcut="0"
Welcome="-1"
SilentInstall="0"
ProductName="VirusScan Professional"
RemoveSetupFiles="0"
CDRomBuild="1"
MISInstall="-1"
CreateUninstShortcut="0"
change SilentInstall="0" to SilentInstall="1"
3) If you're trying this install from the file VSP80EN.EXE then run the program first and wait for the Eula screen, then browse to %user profile%\Local Settings\Temp\vsp8.tmp and copy all of the files out.
4) After this, you should only have to run the attached program for a silent install.