Not sure if you help

Question

Not sure if you help with software problems but its worth a try.I recently updated from office 1997 to office 2003 student/teacher edition. I need to do extensive edit to many old Word documents by changing format. Word 2003 does not seem to like copy and paste when moving information from one document to another. It changes font/size/type and format eraticaly. Microsoft is no help at all. Any suggestions?