Run the installation program again. Is that a problem? What operating system?
i had to refresh my PC and when I did it removed all of my programs. I'm trying to put Lightroom back on and it says my serial number isn't correct. I have windows 8
Are you sure the serial number is for the right version? I don't want you to post the entire serial number. But there should be six groups of four numbers, and the first four should be 1160. Does your serial number meet that criteria?