In this case I had an OEM load of XP on the one drive.
I used a partition program to make two new partitions.
I Installed Windows 7 RC on the last partition.
Worked fine, but I thought I would try to re -install XP.
XP would not add Win 7 RC to the boot menu.
So I had to re install Win 7 RC and it works fine now.
The question is what went wrong?
Apparently XP will not try to put the newer OS in the boot menu.
But is that the exact answer?