Try going into Disk Manager and assigning the drive a letter, maybe it gets messed up somehow.
 
btw, I wouldn't use those dynamic drives unless you need 2Ks software RADI etc, cos DOS will be unable to see them, nor will utilities such as Partition Magic be able to manipulate them as I found out with great peril.
 
..I'm as yet to find a way to format a drive in 2K that doesn't results in creating a dynamic disk! I had to finally format under a DOS session.

Was the system at SP1 before SP2 was installed? The reason I ask is that, since the service packs are cumulative, your friend might be experiencing a W2K SP1 bugaboo that whacked a lot of Maxtor drive users. You might want to check out this MSKB article. Since the article is written primarily from the perspective of a single drive user, the exact presentation of the problem is different. I suspect that the two drives are configured differently on your friend's system and that the second drive is being affected by the syndrome described in the article. Fix is easy enough, so I hope that this is it.
 
Whatever the proble is, I hope your friend finds a solution.
 
Regards,
Jim