Originally Posted by JeremyT

Yes, with IE8 shut I've set all the zoom reg key values to 0, and the zoom factor to 80000. But as soon as IE8 is restarted the zoom factor always goes back to 100000 in the reg key, and 100% in the browser's settings display.
I have no registry guards installed; just Eset Smart security (Antivirus/firewall), which I've disabled when attempting to make changes. It's as if these settings were welded into place!

Thanks for your help.