I have an HP photosmart 7760 printer. when i try and print 4X6 i get the error ';Unsupported Media Size'; why?

Did you go into the settings and change it to 4x6 so it will print on that size of paper. Paper size is not immediately automatically detected when you print. I have an hp 7760 printer that I use all the time. Did you remember to slide the paper lever in so it prints on the 4x6 ? There should be two settings for this one is 4x6 and the other is tabbed 4x6 which is generally photo paper. I hope this can solve your issue.