You need to resize it silly.

Quick resizing fix:

Just about every computer has "Paint" as a program.

Right click your picture and choose "Open with" and select the program "Paint"

Go to the toolbar and select "Image" , "Stretch and Skew"

Reduce the vertical and horizontal fields as much as you need to compress the file but adjust them evenly.......say 50 and 50.
See what it does to the picture. (It not only reduces the pixel width dramatically it compresses the file size as well.

When you get it under the maximum requirements for a file upload here save it and try again.........it should load up no problem.