when i put new hard wear it wont run?

when i put new softwear into the disk drive it wont run any disks what so ever, a friend has had a look and says that the drivers for my ADVENT 7081 LAPTOP has not got the drivers there for them to run this, it used to work ok but now it dont ,can anyone help??? ppppplllllllllleeeeeeeeeeeeaaaaaaaassssssssssseeeeeeeee!!!!!!!!!