Adobe flash is not installed on a PC

I know this is not the right forum to ask questions on Adobe, but I have tried all the resources on-line and I am on my last leg.
I have recently upgraded my explorer (IE) to the latest version, but have been regretted it every day.
I have installed Adobe and Flash at least 15 times, but it is not recognised on my laptop, so I do not have it, despite the fact I can see physically installed. I can open PDF files using Firefox, so how that Adobe site keeps telling me it is not installed on my PC?
The first step I took was to turn for help on the Adobe’s site. I have read all the instructions, questions and help, but nothing has resolved the issue. I was told to remove all adobe products and re-install them. I have done it many times.
I am posting on this site, hoping that someone else had the same problem as mine and managed to fix it.
So far, I have done the following.
Remove and re-install as per Adobe’s instructions.
Disabled autofilter on security options.
Added Adobe on compatibility view and adds-on.
Enabled Flash on ads-on (Has already been enabled).
What else I am missing?
I do not have any problem using Adobe with Firefox and have been using Firefox, but I need IE.
If removing IE11 and re-installing the old version solves this nightmare, I will do it.
This is not isolated problem by the number of people asking the same question, but MS or Adobe have done nothing to resolve this issue.
I am using IE11 and have Window 7.
Please any help would be appreciated.

Hello snb,
Thank you for your suggestion!
In IE, there is a menu called "Compatibility view settings". I have already included "Adobe" on the list, but this does not help.
What frustrate me is I can see and use "Adobe" on Firefox, but when I go in to "Adobe" site to test if it is installed on my PC, it says, no. I have tried all of the possible solutions on the site.
I have wasted a couple of days on this crap. I feel the best option right now is to remove IE11 and reinstall the old version.