My all in one Lexmark X5150 will not scan (VISTA)

[P1kARaT]

Hi;
I have an all in one Lexmark X5150 and when I push the scan button and scan to file it will not scan to the computer. I have a windows VISTA and I had the same problem with XP, but my father did something on the computer to make the scanning option work. Both he and I forgot what he did and we do not know how to scan pictures, ect. to the computer now.

Help is greatly appreciated; thanks.