SandraWeisz wrote:Hii,,,
I have found saving my libre office docs in the older ms word 97 format works best, it gives the .doc extension instead of the 2007 .docx extension. same thing with powerpoint ppt instead of the pptx. In libre office I set the options to save in that format by default.
I have ms office 2007 at work and don't seem to have a problem going back and forth with the 72/2003 formats.

This is what we try to explain all the time on this forum.
a) Save all your work in the native ODF file formats (.odt .ods odp etc).
b) Send PDF to others for reading (FIle>Send>Email as PDF). This is the one and only file format designed to look like a virtual print out of the original document.
c) Send MS Office formats (.doc .xls .ppt) whenever you've got to co-edit office documents with someone having MS Office only (FIle>Send>Email as doc/xls/ppt). After decades of co-evolution, this is still the foreign document format best supported by OpenOffice. It is not recommended though to do your daily work with foreign file formats. Just send doc/xls/ppt copies when needed and save your own ODF copies when you receive a foreign file format.
d) If the MS Office user has the latest version of MS Office, you may send ODF (.odt .ods odp). Since 2010 MS Office supports ODF fairly well, may be not as well as OpenOffice supports doc,xls,ppt.
There is no technical reason to use the Microsofts latest office file formats called "OOXML" (.docx .xlsx .pptx). Until today there no software other than MS Office is able to handle these file formats properly. From the MS point of view this is a good thing. OOXML is not a viable option.