|Double click some jpg picture files you already have on your computer (mostly in My Pictures). If they open then then the suggestion in #1 is probably correct.|
If the above works download some pictures from another website to see if they open. Also right click some pictures on websites to see if they can be saved and then opened. We need to work out what particular situation causes your issue.
Give us a link to one of these problematic downloads.
Always pop back and let us know the outcome - thanks