CD/DVD drive not showing in "My Computer"

My drive doesn't show up in "My Computer". When I go in to Device Manager there is no listing for DVD/CD-ROM drives. But when I "scan for hardware changes" it shows up. I'm using a HP dv9815nr laptop with Vista Ultimate 64-bit and the drive is listed under Device Manager as a TSSTcorp CDDVDW TS-L632N ATA Device. I don't know if its a driver issue or something else. I've tried to update the driver, but it says its up to date. The problem started a few days ago after I hooked up a new WD My Book Essential 1TB external hard drive. After reading other posts regarding CD/DVD drives I disconnected the drive and uninstalled the software that came with the hard drive and restarted the laptop. Unfortunately my CD/DVD drive still didn't show up and I had to go into Device Manager and rescan for hardware changes. The drive does work after I rescan, I've burned a couple CD's and played a DVD. Its more annoying than anything else, but I have a sneaking suspicion this might become a permanent or larger problem. I'd appreciate any help (keeping in mind I'm not that computer savvy). Thanx.