This file is designed to be imported directly into LMSs and is not designed to be readable with the regular programs on your computer.
This file has passed validation against the standard at http://validator.imsglobal.org/cc for CC 1.1. Most LMSs support importing from this format into their system.
Here are some instructions provided by the major LMSs for this task:
You may want to ask your institution’s IT department/departmental LMS liaison for assistance, since LMS instances vary from institution to institution.