• Why has my page layout changed when I open my document on a different machine? by Suzanne Barnhill, MVP
• What happens when I send my document to someone else? Will Word mess up my formatting?
• What must we do to ensure that one and the same document is displayed - Microsoft Community

What you are seeing is far from unusual.

I suspect that the above links will tell you what is happening, why, and what you can do about it. If not, please write back and possibly attach a sample document giving you problems. Tell us what you have tried (specifics, not "everything").

How to attach a screenshot or file in this forum.