This usually means your search is too general. Doing a more specific search will help reduce the amount of records you retrieve. Below are some ways to refine your search.
If you used an asterisk, omit it and try an exact search instead. For example, search forcomputer technology rather than comp*.
Try using the Boolean operators &, /, and !, or the AND, OR, NOT drop down menus to construct more precise queries. For example, to find records relating to Simcoe, but not John Graves Simcoe, search for Simcoe ! John.