Protip, go for Windows 7 instead of XP, and don't dualboot anything, just install windows7.

 

just split partitions, best bet is to use a linux disk to do this, but to be honest 2 windows partitions is useless and just take up more space then needed, i dual boot but i dual boot ubuntu and windows 7

 

Install XP, then use the vista disc to install the vista bootloader again, since XP's won't boot vista. If you lack an actual vista install disc (just a disc that automatically "recovers" for you), use somebody else's.

But unless your computer's specs are absolutely terrible (like, a gig of ram and integrated graphics), go for windows 7 instead, it's much better than XP.

By the way, what is it you can't do with vista?

 

Mei-o, you asked for an easy step-to-step dual-booting guide for Vista/XP with Vista installed first.

Here's the link: h**p://apcmag.com/how_to_dual_boot_vista_and_xp_with_vista_installed_first__the_stepbystep_guide.htm

 

The page opens normally, check your firewall / ip filter.

EDIT: my error, extension is HM instead of HTM. Corrected.

EDIT 2: the forum changes the URL. Who can explain me why?

EDIT 3: I had to bold the extension (bah...). Mei-o, just substitute h**p with http and then go to the page.

 

You will need a vista or 7 disc in order to replace the XP bootloader with the vista/7 version.

Get a disc, you can use somebody else's.

But again, what is it that vista won't let you do?

 

I agree and specify: restoring the bootloader with the Vista disc will overwrite the informations about XP, so dual-boot won't appear.
EasyBCD will help him to get the right informations and to build the right bootloader.