Help!! Please!!

[nlewis]

I've got an HP Pavilion laptop that runs Windows xp. I just installed a new external hardrive, Seagate, and now my CD-Rom doesn't work. It was working the last time I used it, but after I installed the ext. hd. it didn't. I've tried everything I can think of, but it appears as if my CD-Rom has dissapeared all together. When I insert a disk it acts as if it's reading, but nothing happens. Any help would be greatly appreciated!!!