Scanned images enclosed into PDF file, result image-based PDF file that has no text layer.
When converting such document to MS Office document the resulted file will consist of images only.
OCR (optical character recognition) function helps on scanned files (any image files) to have the text extracted.
The latest Expert PDF 10 provides OCR function for 8 languages only in the Ultimate edition.
With Expert PDF 10 Ultimate you can create editable text for Spanish, English, French, German, Italian, Russian, Japanese and Portuguese language.
If you own other edition of Expert PDF, order OCR license from within the software.