Downgrade from Internet Explorer 11 to Internet Explorer 9 on Windows 7 Pro 64

We recently received a number of Lenovo desktops with Windows 7 Pro 64.
They came with IE 11.

For compatibility reasons (3rd party driven), we *must* downgrade to IE9.
But, IE11 does not show up in the Installed Updates list.  In fact, the Installed Updates list is very short!  It has but 24 items showing.
So, we can't uninstall IE11 as there is no choice available.

We can't just install IE11 on top it because a "newer version is already installed".
We can't just install IE9 on top because of the same thing.

I notice that there are IE folders in both Program Files and Program Files (x86).
I see a file ie9props.propdesc on another Windows 7 Pro computer in both the Program Files\Internet Explorer and Program Files (X86)\Internet Explorer .. but I don't know what this means in the context of this problem.
The only thing we can do is to uncheck Internet Explorer 11 in the "Turn Windows Features on or off" dialog.  But, of course, this really does us no good.

There are no workarounds permissible (like using Chrome).  So we have to get this resolved by getting IE9 running.