My MAC jpegs won't open on a PC?

I took pictures with my Nikon camera. Put those pictures on my friends MAC then onto a USB. Now I can't open them on my PC. I have tried opening them using Photoshop, Windows viewer and paint. Still can't open them. The files look like._IMG_xxxx. Any suggestions?

Add.jpg to the end.

All files that begin with._ should be ignored or trashed. They are resource fork files that apply only to old classic Mac OS 9 and older. Those are invisible in OS X Finder, but Windows isn't based on UNIX, so it doesn't know all files starting with a dot should be invisible.

Scroll down the list of files to get past the ones that begin with dot underscore. You will see the real photo files.