Right click it and on the drop down menu it says "open with", then pick paint or it might say "edit", if it does, then click that. When it opens in paint, theres a menu on top , pick rotate, when it shows a box, pick 90 degrees. It'll change. I use paint a lot. And also, when viewing it on your normal photo screen, this might be easier for you, there are 2 mountain looking things at the bottom of the pic. One rotares it right 90 and one rotates it left 90. Click that. It might ask if you wanted to change it. say yes. and rotate through all your photos and all that are in that session that you do that to will stay that way. In that file, if you have copies of those pix somewhere else in other files, they might not be affected.