Hi Chloe
I think drummachine's (DM's) script of June 19 won't work now because the old version of Windows10 is normally automatically deleted 10 days after the update.
So here's a step by step using DM's copy of the .dll file that fixes Windows live Mail (WLM)
1.To download the magic WLM fixing .dll . . .
In your own post of
July 17, (page 9 or just above this reply), where DM's text says:
"Here is a copy of the old .dll"
just click the coloured
d3d10level9.zip
This opens One Drive in your browser and shows a picture like this:

Click this picture and a Save As dialog opens; save the .zipped folder somewhere convenient (I used the folder suggested by the dialog, called d3d10level9, too) and close the One Drive
stuff in your browser.
- Now, to unzip the zip folder . . .
Go to the place where you saved the .zipped folder and click it; you will see the .dll now in the folder.

Right click the .dll and click Copy.
- Finally, to put the .dll in the right place to fix the WLM problem . . .
(In File Explorer) select MyPC or ThisPC or whatever yours is called and click the system drive,
usually C:
Scroll down + click Program Files(x86)
Scroll down + click Windows Live
Click
Mail . . . you'll see the files that WML uses . . .

and then click Paste, top left.
You should now see d3d10level9.dll listed among those files.
That's it, all done, close all dialogs and when you next run WLM all should be well.