Dual install XP/Vista, hide partitions on each OS...

So as expained in my previous post, I managed to make a clean install of XP and Vista on my laptop, now for security and after an error I did (had to reconfigure some rights for several files from Vista to make XP work again...) I'm searching a solution to hide XP partition when working on Vista, and of course hide Vista partition when working on XP. The solution of hiding it "hard" is to forget, cos on next boot a system or the other wouldn't load. So is there a solution to hide a system partition when working with the other, that wouldn't make a mess in drive letters or something like this ?
Any soft able to do it simply on xp ? and perhaps the same or another on vista ? I'm a little lost and don't wan't to crash my system, of course. Thanks for answers.

 

You may be able to use Grub? tho I have never personally attempted to execute such a feat on my own.. you do not need to install linux to use grub but how to use it without it is beyond me but some linux forums may be able to steer you in the right directions.

 

ok well I wrote a lot of text here and this damn page refreshed by it self - all my text lost - lame.

oh well, guess I'll make a blog post about my findings.. waste of time signing up here.