How to convert doc to docx
1.way (Microsoft Office NOT required)
-Microsoft Office Compatibility Pack - here
-Microsoft Office Migration Planning Manager - here, (older version here)
Install both programs.
edit ofc.ini from the second program. It is in the folder where you installed it.
or use some of these programs:
-doc2x (command line tool) here
-libre office here
-wps office here (The one from wps.com has expire date for saving as doc/docx.)
-abiword here (Can be used from command line)