那个信息是有可能你以前修过，但是drop了，the officer needs to do an overwrite to that course so you can register it again.
another potential possibility is due to course restructuring, say a course AAA\'s prerequisite is 222, you have done 222, but now the course 222 is changed to 228; then the system thinks you don\'t have it.
I agree the system is really stupid, either scenario you have to see your faculty advisor.
about computer science course routine, it\'s recommended to read this page http://www.cs.umanitoba.ca/newsite/undergrad.htm, move your mouse over Areas. The same information can be found in the calendar.
determine which area you want to go, then complete the required prerequisites. there is no general pattern, because different people might have different interest.
