I found the answer if anyone else needs it... it's here:
http://windowshelp.microsoft.com/com...7-aaf08f747382
"ScottGeordieKid" wrote:
> I created a partition in XP, and installed Vista on it. It's now my default
> OS, but I want to go back to just XP. How do I do it?
>
> I was thinking if I go into XP, delete the partition with Vistaa on it and
> merge the two back together, would that then just default into Win XP on the
> next boot?
>
> (If you can't tell, I'm a bit of a advanced novice - I understand some
> things, but have a patchy knowledge on a lot of things...)
>
> Best,
> sgk