COMPUTER PROBLEM PLEASE HELP!?

I did the icon prank on my brother computer were u take apicture of the back ground and save the icons in a nother file so he clicks the icons and gets pranked. i put the file with the icons in My Pictures file. after that the prank was over and i told him. but his computer turned off and wont turn on will his all his doents get erased and does he have to reformat the computer wut do we have to do to keep the files.