AV2009 installation not installing due to detecting a previous Norton product

I’m trying to install Norton 2009 in a Vista 64 bit machine.  There is a message that the installation has detected another Norton product and then proceeds to uninstall it.  Then after a short time, I’m told that the machine must reboot to continue the installation.  But after the reboot the whole thing starts all over again - the detecting, clearing, and need to reboot.  I’ve found out from troubleshooting here at Norton the trouble is a temp file is not clearing on the reboot, and I downloaded a tool to correct it.  But the tool says there is nothing wrong found.  In fact I don’t have any previous verson of Norton AV anymore on my machine! I did a regedit and deleted all entries containing Norton - but no help.  I tried a search here in the forum and nothing came up.