Some good news: I made NTLite build #53 with IE8 left in this time. Dragon is working again.
I was beginning to hypothesize that this was a DEP problem. Apparently not.
After I make a backup, I'll see if I cwn remove IE8 with Windows' Features. (I had removed IE before on my old Win7 and Dragon kept working.) If I can't do it via Features, I'll try via NTLite Live. I'll plan to report back later.