win 98 problem

one mc working with win 98 and realplayer 7x , i have one cd with adio as well as vidio ,when i run that at that time it run for 5-10 minut ,during this time i herd sound perfectly as well as see adio perfectly parally from one cd only, but after this time vidio is stuc up but sound herd perfectly , if i format and reinstall win98 at that time both work perfectly