problem (immediate)

hi i m using fedora core 6 at home on my pcand i dont have a cable connection
 but there is a problem that every time i click on the" ADD OR REMOVE PROGRAMS
 " it shows this messege 

Unable to retrieve software information

Unable to
 retrieve software information. this could be caused by not having a network
 connection

Details

cannot find a valid base url for repo: core

 

 how can i
 solve this plz help me and one more thing how can i add programs from my
 fedora core 6 dvd to fedora plz help best regards  plz reply

 

mk18_2003@xxxxxxxxxxx

 

bye