KB891711 is a Windows update which has caused problems with some OS's, including Win 98se.
If you read the discussion on the forum below, it will explain more. Some friendly advice: If you Google the contents of any error message, as it appears on your screen, invariably it will come back with a wealth of information on the problem and its manifestations!
http://www.computing.net/windows95/wwwboard/forum/164531.html