A8N-E Boot from P-ATA if I also have SATA RAID installed

I was running A8N-E with two "old" parallel ATA hard drives with
Windows XP SP2 installed. Recently I bought new 2 SATA drives and
wanted to configure them as additional RAID 0. Unfortunately system
tries to boot from new RAID array not from old P-ATA and of course it
fails and halts.

Setup configuration utility does not offer to change boot device
priority of hard drives. There is an option in RAID configuration
utility (F10) to make array bootable but there is no option to make it
unbootable. By default this option is set to unbootable but the next
time I run this utility I see this option set to bootable.

Is there a solution for my problem?