At this time, the library does not recommend that you utilize the Referencing option in Word. Other free software options like EndNote, Mendeley, or Zotero are much more robust and let you more easily gather and organize your references.
If you have started a reference library in Word, you can try to export this data into one of the other bibliographic management utilities. The conversion might be a bit messy. See the directions at the University of Waterloo library.