Can't set IE11 as default browser

I have visited this forum before, but just joined today to try to get a solution to my problem:
I can't get IE11 set as my default browser (and it's the only one I use and have installed).
There's an old thread dating back to March 2014 talking about the same problem- a pop-up every
time I open IE11 that asks if I want IE11 as my default browser. I have answered that "yes" dozens of times
and also used the Tools/Internet Options/Programs-"Make Default" button, and none works.
(That thread was called "Browser won't remain as default")

That previous thread ultimately gave a 5-step solution and I follwed those:
1- search for specfic programs and uninstall- I didn't have the Delta one, but cleaned out
some recent installs that may be issues;
2- remove Delta browser hijacker with Adwcleaner- I have used this program before, and ran it again-
it did not find Delta or much else, but cleaned out nevertheless- (Adwcleaner worries me, inasmuch as it
seems to disappear from my computer every week or so..?);
3- run Junkware removal tool- did that and it cleaned out one or two items;
4- run Malwarebytes Free- I use this regularly- this time at found a few items;
5- run HitmanPro- did this also
None of these processes solved the problem- (that user did a repair/install of windows 7 finally)

This morning I tried HijackThis- the log has some strange things, like blank files and even missing files,
but most do not seem Delta-related and I'm not sure what to do.
So I am at a loss for "next" step options.
I have recently been searching for (1) a comic-book reader program because I am a western book collector
and have had issues with toolbars, but am careful to uncheck all those installations, but PUPs and other items still get on but have been removed with the 2&4 options above, and (2) a youtube downloader because I'm trying to build a quasi-karaoke system for Christmas-with-the-grandchildren and I get the videos from You-Tubeand words and chords from other sources.

Overall my system starts ok, but sometimes is slow just bringing up Excel, sometimes I get a lot of "Not
Responding" messages on the internet, and sometimes, when I check Task Manager to see what's running,
I see multiple iexplorer.exe *32 entries (there is 1 now, at 92997k, one tab open) plus 1 iexplorer.exe at 19000k). But I have seen an entry for iexplorer *32 at as high as 490000k, which seems terribly high.

My toshiba laptop came with Windows 7 SP1 with an auto-install feature that started when I turned it on,
but I don't have disks. I do have Windows 7 disks purchased new approx 3+ years ago. but alas, I have tons of software that I don't have disks for, and my Excel disks are for 2003, not the 2010 that came with the Toshiba.

In one thread, it was suggested re-downloading (from Microsft directly) and re-installing IE11, which I did:
the message I got was "Setup cannot continue because my installed version is newer (than downloaded from Microsoft!!

Sorry for the long blurb, was trying to give info that you might ask for.
And speaking of asking, can anyone help me with "next steps"?
Thanks for reading.
Wayne

To Thrashzone- I typically disable ALL add-ons unless I think I need one; they are currently all disabled
as per sceen shots attached. I did have two entries for the Panda Toolbar, but removed those yesterday,
still having the problem today. For a short while, like 10 minutes, Google Chrome came with, I think, a Malwarebytes update. I immediately uninstalled it, but noticed yesterday there are many many entries in the Registry for it.

To both ThrashZone and Gornot- thank you both for reading and replying.

To Gornot- I rebooted, checked in Task Manager to make sure there were no "iexplorer"s running
and went to Default Programs/Set Default Programs.... and waited, and waited, and...there's nothing listed!

To ThrashZone- discovered taht when looking for All add-ons listing (which I sent earlier)
does not include ones under Run without permission. There are quite a few enabled, but all Microsoft.
New file attached.

[QUOTE=also check the search providers section too and report back .[/QUOTE]
To ThrashZone- missed the above... my only search provider is Google, as default-
I tried Bing but preferred Google, there are some entries in Registry for it.
Believe at one time Yahoo was offered but don't think it was iinstalled, but there are entries in Registry
for Yahoo Toolbar, Search, etc. No program iinstalled.

To Thrashzone- thanks re the pointer for JPG vs doc file
I could set the prompt to not show the message, but that would just hide that there was a problem (whatever
it is).