Press Ctrl+F8 to delete all text and vectors that were recognized last time you used Run Menu > OCR, Run Menu > Vectorization or Run Menu > All.

Press Ctrl+F6 or select Run Menu > Undo OCR to delete the text that was recognized last time you did a text conversion using Run Menu > OCR or Run Menu > All.

If you recognized text using Select Color Layers, only text in the last color that Scan2CAD processed is undone.

Press Ctrl+F7 or select Run Menu > Undo Vectorization to delete the lines, polylines, circles, arcs or Bezier curves that were recognized last time you used Run Menu > Vectorization or Run Menu > All.

If you recognized vectors using Layer Colors, only vectors in the last color that Scan2CAD processed are undone.

Any edits you have made to the text or vectors since doing the vectorization are lost.