Best posts made by dotbox

@burnout426 I've already done/tried all that with defaults; I uninstalled IE years ago.
I've gotten pretty comfortable with Opera now, but maybe I'll just move over to Brave or Vivaldi after all.

@burnout426
Thanks for your help on this. I suspect that somehow I missed choosing 64-bit on the original install. I still can't figure that one.
I was checking to see when I actually installed it; I downloaded and installed it last Jan., but here's another "wtf?." Opera shows up in a search, but if I just try to go there with Explorer, the folder isn't does show. I'm sure I didn't hide it, so there's another reason to un/reinstall.
Also, as to why Vivaldi, I listened to several review and analysis of the various top (3-5) and decided on Brave, then a demo and further comments sent me to load up Vivaldi. Since I've been using Opera and tried a bit just finding my way around Brave, then Vivaldi, if Opera works as it should with OE, I like having my workspaces and will probably just stick with it after all. Unless something happens to convince me otherwise.
In the meantime, I've still got to get some other $#!^ done before I tone for my sins against Opera.
Thanks for setting me straight, if this works out, I might want your help tuning an ATV I've recently acquired.

@burnout426 I got no chance to "Make Opera the default browser"
What is "Opera Stable"?
Problem persists. OE giving similar error notices as before.
Opera not listed in Default Programs but is in assigning file associations. Opera Setting says Opera is the default.
When was Opera supposed to let me choose it as Default. I remember this being peculiar somehow before.
I backed up my Profile folder, but was presented choice to keep the during first part of install.