Lost CD-RW drive

I recently took my PC down to barebones to try to troubleshoot the PC freezing up. I had two hard drives, one of which is partitioned. I left one in which I thought was the primary drive, but it ended up begin the slave (?). I managed to boot andreload Windows, etc., all the way up to reinstalling all drivers, etc. By the way, no resolution on the freezing up. So I put the other hard drive back in this morning, the OS assigned the letter D and E to each partition, but now my CD-RW, formerly D: is gone. How do I find my CD drive?

Windows 98
AMD Athlon 900
128 mb RAM