Hard Drive Installation Problems

Replaced a 13G Quantum Hard Drive with a 60G Western Digital Hard Drive. I have a 40G Maxtor Hard Drive as a slave. This hard drive is loaded with info that I want to retain. My problem is the computer reconizes both the 60G & 40G hard drives in theSystem Devices but will not allow me to access the 40G. It has assigned letters C&D to the 60G.
Computer Info
Compaq Presario 5457 (475 Mhz)
OS Windows 2000 Advanced Server
Master HD Westerrn Digital WDC WD600BB-75CAA0 (60G)
Slave HD Maxtor a8t/r50404 (40G) Value 200 Pts