i asked once how to make pics bigger, and plebans told me it was impossible...or u will have a bad resolution...or u need to be register in the website where u found the pics to see the bigger versions...
Pics that size can usually be enlarged a little, not much. The ones that can't be are the thumbnails of pay services like Rexfeatures and wireimages. They are too low resolution and only stretch and blur. I think they do that on purpose so you'll have to pay for the bigger ones. (on wireimages the bigger ones were never that big or clear though ) I can't enlarge right now, my computer is too slow and it would take forever