All my pictures .jpeg have been converted to PDFs why?

[lizzylizz]

All my pictures .jpeg have been converted to PDFs and when I click on them I get the following error message: Adobe Reader could not open because it is either not a supported file or because the file has been damaged (example, it was sent as an email attachment & wasn't coded correctly.)

I am trying to open them from the File Explorer /pictures/  and the 'Type' column reads Adobe Acrobat.   I have never changed any .jpegs into adobe.

When I open Reader and look at Pic File Folder nothing shows up. This seemed to have happened some time in the last couple of weeks.

I am using Win 8, all up to date , ASUS laptop, Chrome 

[try67]

I'm willing to bet they didn't change. Reader isn't even technically capable of doing that.

It's the file-extension association that got changed, by accident. See above how to fix it.