This has occured not only from OS to OS, but from Word version to version and even from one machine to another.
You get to sort out if the FONT in question is the same on old/new/other machine and if not, how to install said font.
My work computer was recently upgraded to from Win 98 SE (with Office 97) to WinXP and running Office 2000.
Since the upgrade all my previous documents I created with Word 97 has lost the symbols I have inserted and comes out as a number figure. Example: Check marks I have inserted in documents now appear as 4 or 3. I have to go back and reinsert all the symbols again which can take a long time to do. Is there a better way to open document created with Word 97 in Word 2000 and still maintain the symbols I have previously inserted?