How to export powerpoint document (ppt or pptx) to a word document (doc or docx)

1. open file in powerpoint: 
choose 'file/save as', 'save as type' select 'outline/rtf'
(The above method will not work if 'outline' is empty.)


2. open file in powerpoint: 
choose 'file/send to', 'microsoft office word' select 'outline only', or 
'notes next to slides', together with 'paste

3. convert ppt to pdf, either directly from libre office (file/export) or by installing pdf printer, 
and printing ppt to pdf.

a) After you have pdf, open in it adobe reader.
Use either 'file', 'save as other...', 'text', or 'edit', 'copy file to clipboard' and paste it to word (edit/paste)

b) You can also use ocr in pdf-xchange viewer, which is free. 
Open document in this program, then select from the menu: 'document'/'ocr pages' ., select 'download', 'exe installer'
(This product is free, 'buy now' button is for other products.)

4. If you have text as images in ppt file, convert pdf to tiff using ghostscript, and use tesseract for ocr.
There is info on this site how to do it.