Lord of the Rings battle for Middle Earth 1-2-raise of litch king

Id like to open a discussion about a issue I'm having with the game in hopes other will help me, I have recently gotten a hold of a couple physical copies of the battle of middle earth 2 as well as the lich expansion. Unfortunately for some reason my computer won't recognize the expansion CD. The game are almost in perfect condition zero scratches, and when I close and reopen the disk try the physical game moves. But for some reason the computer just can't recognize the expansions physical copy as a CD. any help with this issue would be great please. All 6 disk for middle earth 2 were read just fine by the computer and I've been playing the game as well just fine but I can't get the expansion to get ready by my disk drive I suppose. . Not sure please help!