Question : Problem: SATA Disk 0 and Disk 2 appear to be reversed

I have replaced my mainboard and am gradually getting things back. In Disk Management, my windows drive shows as Disk 0 and my programs drive shows as Disk 1, just as it should be. However, the computer won't boot unless I change the boot order in the BIOS to boot from Dive 1. Can anyone tell me what's going on here?

Answer : Problem: SATA Disk 0 and Disk 2 appear to be reversed

sounds like disk 1 has the active partition and required bootstrap files on it (ntldr, boot.ini and ntdetect.com).

These articlae may help
http://support.microsoft.com/kb/555304/en-us
http://support.microsoft.com/kb/228004/