Need to isnatll windows 7 on dual boot machine

view story

http://askubuntu.com – I have dual boot configured with Windows 7 (32bit) and Ubuntu 12.04(64bit). I installed Ubuntu after windows, now my windows is corrupt due to some virus and I need to reinstall it. Currently when I start my PC, grub loader comes up and I need to select Ubuntu or Windows. I was wondering how can I install windows again and still have my Ubuntu install? Is there a way to do this? I do not want to install Ubuntu again and lose my settings and data there. Thanks, Ketan (HowTos)