everything saved as PDFs

Hi,

I got a trial sub to Adobe Pro DC and have canceled after a terrible two months. It has laid waste to my files turning everything I download into pdfs. And to make matters worse I am regularly unable to open these pdfs, getting an error message.and saying "a link may be broken".

I have looked on here for how to change this. I'm told to right click and choose to save as something else. But only get three options "snip and sketch", Adobe, or "Paint". I'm pretty sure none of these are how my jpgs were opened before. 

Please can you tell me how I can undo this horrible, intrusive default and also change these pdfs into openable jpgs.
Thanks!

Ben