okzz this is what happened.. i was earlier using windows 8.1 with dual boot Ubuntu 14.04, updated it to 15.04.. there was some bug after i updated it (desktop went all black after i updated it, although not relevant...) so i downloaded 15.04 iso made a bootable pen drive and reinstalled Ubuntu 15.04. this is when things got messed up... now my laptop boots directly to Ubuntu. although i can access my windows partition from the Ubuntu... it just doesn't boots to the windows. i already have tried that boot-repair.. it still not showing windows although after that it started showing that purple screen where i can choose what to do... help.
p.s. i dont have any windows cd or a recovery pendrive
sudo update-grub
in ubuntu terminal.