Could you post the exact text of the error? I'd like to run some searches and that would probably help in finding the most relevant results.

It does not stay on the screen long enough to write down. "Illegal action" it does say, and one or 2 other words flash before it disappears and then my computer goes dead (or should I say it stops dead) and has to reboot. I would love to find a disk to load Firefox while offline, so it is ready and waiting to pounce on Explorer8 when I go online, instead of the other way around.

You can download the Firefox installer to a USB flash drive or CD-RW at a public library or a friend's house or a colleague's PC. Just make sure that if you have a different OS (e.g., Windows vs. Mac) that you get the correct version. You can use the "all" page for that:

http://www.mozilla.org/en-US/firefox/all.html

You also may want to grab some anti-malware tools while you're at it in case the process rejecting Firefox is not IE itself but an infiltrator. These two tools are highly regarded:

Malwarebytes Anti-malware : http://www.malwarebytes.org/products/malwarebytes_free

SUPERAntiSpyware : http://www.superantispyware.com/