One other after-thought....it seems since you have the skills to run multi-boot and if your searches for a solution doesn't result fairly fast, what I would do (of course, you are not me) is solve it rather quickly simply by re-installing XP in the proper partition...if you are not running multi-hard drives...yet that doesn't matter, same principle.
If I have a problem and I can't fix it fairly fast, I get out my gparted disc, reformat that partition then make the drive/partition ready then re-install.
Then I (if it isn't already installed) use easybcd to get the OSs named and numbered like I want...there are different ways to do all this so one doesn't have to use the same tools....
I generally have the drivers I need already for each OS stored for relatively fast getting it back going.
Anyway, it's according to how much stuff one has connected, various hardware items...I know I can install XP in about 50 minutes on my laptop....W7 in about 25 minutes...takes longer however for my desktop due to all the extra stuff.
I'll nuke my OSs in a heartbeat if something isn't working like I want.
Likely though my way is not the standard way of dealing with issues...