I have been using win7 and ubuntu 11.04 in my laptop - hp pavilion dv6 -1110ax. Win 7 crashed recently for some reasons not known and i decided to reformat the hdd completely and install fresh copies of win7 and ubuntu 12.04. so i booted from my ubuntu 11.04 dvd and formatted my hdd completely in Master Boot Record and out of the 320gb, i partitioned 90gb out from the beginning and formated that in ntfs. then i came out and booted from my win7 disk. Nothing comes apart from a blank screen with a blinking cursor. when i boot from ubuntu dvd it starts working in charm. Also i could go a few steps of installation when i inserted my old winxp disk (winxp cannot be installed in my laptop which was discussed elsewhere in the forum at length). what is the problem 
