I merged your previous threads as I thought it added clarity to the present issue.
Just trying to clarify: now you have two drives with a copy of XP on both?
One is SATA and the other is ATA?
Are you sure you know which one you are booting into?
In general your C: drive will be your Operating System.
There can be some strange issues mixing SATA and ATA drives especially if they both contain XP.
All this should be clear in the Disk Management section:
start Run...
diskmgmt.msc
Also a 10GB partition for XP SP2 can be quite limiting in the future (especially since you have so much space).
Hope I haven't completely missed your point.