My friend have installed Win XP and Vista Ultimate on same pc but later he reinstall the Win XP and now pc directly boot to Win XP directly. I try to edit boot.ini of Vista?
Vista doesn't use boot.ini anymore... it's boot-loader is completely different from XP's boot loader. The only way you're going to get it back is to do a repair from the Vista CD.
use bcedit.exe in the command prompt.. alternatively download vistabootpro it's a gui version of bcedit allowing you to adjust your boot options with ease.
Your friend will have to do a repair from the Vista disc to get vista booting again. as for dual booting, try a program called EasyBCD. This will help setup the boot options.
You are about to answer a thread that has been inactive for more than 6 months. If you still wish to proceed, please ensure that your posting is original and does not duplicate or overlap any prior responses to this thread.