On Windows 8.1 you can Export comments with free Acrobat Reader DC. The function will export the data to FDF or XFDF format.
Open PDF in Acrobat Reader DC and click on Comment tool on the right.
Click on the list icon as mentioned in the screenshot.
From the list you select 'Export Selected to Data File' or 'Export All to Data File'
With Acrobat DC you will get few more options like Export to Word AutoCAD.
Let me know if this works for you.
Thank you. No, this does not work for me. I am only given the option "Export All...". The option "Export Selected..." is greyed out.......
[discussion moved to the Acrobat Reader (desktop) forum]
The option 'Export Selected...' will be available only when a comment is selected from the list.