Uninstalling Norton 2006

I just went through a Windows XP Home -> Vista Home Premium upgrade
and it went fairly smoothly with the exception of Norton Anti-virus.
The instructions said to update your anti-virus program and then
disable it while you are upgrading to Vista. (It should have said
uninstall the anti-virus program) After the Vista upgrade it
complained about Norton Anti-Virus 2006 and it recommended the
download of a newer 2007 version.

We downloaded the 2007 version but the install kept failing. I think
it is because the 2006 version would not uninstall.

I went into the control panel and tried to uninstall the 2006 version
and it almost completed but could not stop some service. Once you
click cancel it tried to undo the uninstall and it is not very
successful and leaves the system a mess.

What I need is a way to manually uninstall Norton anti-virus 2006 or a
way to just stop it from starting up so that Norton 2007 can install.
Anyone? Is there a Safe Mode with Vista?

Al