A family of Microsoft word processing software products for creating web, email, and print documents.
How did you "retrieve" the information?
Size wise you are no where near the limit.
I've got a file just under 50MB that I can edit in 2003 just fine. I also have several in the 30-40MB range. Page counts I have docs in the 1000 - 1500 page range.
You don't "Have to" replace 2003 if it still has all of the features you need. There are many people who are still using older versions.
A file crashing shouldn't (but may) affect your Office / Word installation. If you are concerned, you can do an Office Repair. It won't hurt anything if you do it.
Repair or Uninstall Office 2010 / 2007
http://office.microsoft.com/en-us/excel-help/repair-or-remove-office-2010-HA010357402.aspx?CTT=1