Error loading os after attaching slave drive

[gshrop]

OS Name Microsoft Windows XP Professional
System Model M925
Processor x86 Family 15 Model 1 Stepping 3 GenuineIntel ~1799 Mhz
BIOS Version/Date American Megatrends Inc. 07.00T, 4/2/2001
Total Physical Memory 512.00 MB
Drive C:
Description Local Fixed Disk
Compressed No
File System FAT32
Size 37.27 GB (40,022,605,824 bytes)

After formating (fat 32-4 partions) and installing a WD 120g HD with WD untility, I get the message "uable to load os" at boot.
C: is a Maxtor 40g. If the WD is taken off line, the system boots nomally. Any clues as to what the problem is?

[jmichna]

Is this thread any different than the one you posted in "General Tech Discussion"?
Check back there for responses.
Thanks.