Using Scan2CAD, you are able to rotate a portion or selection of your vector image. You may also rotate the full vector image both 90 degrees clockwise or anti-clockwise. Rotating the image is another way to deskew it.
Rotate the whole vector image
To rotate the whole vector image your vector image by 90 degrees anti-clockwise click the Vector Edit Menu > Modify > Rotate > 90 Degrees Anti-Clockwise