I got it out of the very annoying IE restarts and font security alerts in IE by two things. First, I uninstalled some OEM installed crap programs for telephony and such then followed up with manual removal of their residual directories that I could locate. This got rid of the IE9 restarts. The font security alerts I got rid of by wading through the McAfee AV/firewall configuration. The McAfee has a so called optimizer function and did a deep scan with this. The optimizer found about 2000 registry goofs, active X goofs, file fragments, dead end links, etc. First thing it did in the fix was to set a restore point then fixed most of them.
We stuck with 7 because of the issues, and our major data provider put out a warning about IE8