Sometimes it is just a user confusion
I can't explain why your browsers can't open those JPG pictures, perhaps you are not using the correct commands? Powerpoint is not a JPG viewer. You can use it to place a JPG in a slide, but to use it as a viewer is not its purpose. If you want a great, free graphic viewer, get IrfanView. I have it on all my computers.
I am not saying you ARE doing something wrong, but you may be confusing just how to use an application. I have seen, sometimes, where a person says "I tried that!" or "I tried everything!" and yet when I show up and do exactly what I have told them to do ... it just works. (?? I don't think their computer hates them. )
So, let's see if there is something wrong with any of your files, first, to at least rule that out. Just eMail me (you can do that by clicking on my name and clicking on the link to eMail me). When I get your eMail name, I will send you my eMail name and you can then send me one or two of your files.
If I see nothing peculiar with your pictures I can then, perhaps, walk you through the steps to get your PC working correctly again.