Help. hello sir, i m new user of this site.i have Compaq Presario V6604TU Notebook when i was

Question

hello sir, i m new user of this site.i have Compaq Presario V6604TU Notebook when i was purchased, it was come with windows vista after than i had multiboot system with windows xp.means i load windows xp but after that i m facing many problems related with it....i m not able to chhose operating syatem....whenever i restart my notebook it starts only with xp...there is no prompt for the choice of operating syatem.....so pleas give me information about it...my e mail address is [e-mail] you