I your problem is what i think it is you have 2 options:
1. Scan it again in the correct position. The top of photo the should be positioned toward the hinge of the lid and face down in the corner (the upper right on mine). Then use photo software to crop out the excess white space.
2. You can rotate it on the computer by right clicking on the file and clicking one of the two rotate buttons (Clockwise or Counter Clockwise).
Hope this Helps