Windows 7 over preinstalled Ubuntu

[destructor]

Hello, I got a dell laptop with preinstalled ubuntu 12.04 and now i want to install windows 7, removing ubuntu completely.
I have downloaded the windows 7 iso from torrent site, tried converting the pendrive format to NTFS by using Gparted and then unetbootin for iso files. But when i get into boot option and select the pendrive, laptop does not start with the windows setup instead ubuntu loads. Even i placed the first boot option to cdrom and pendrive none of it worked.
Could someone help me with it. Is thr anyway to get ubuntu off.
PS : I dont want to try virtual window in ubuntu.

 

[tommy_vercetti]

Why not try the official option? http://www.microsoft.com/en-us/download/windows-usb-dvd-download-tool

 

[destructor]

Why not try the official option? http://www.microsoft.com/en-us/download/windows-usb-dvd-download-tool

This procedure would work only if i have windows as an existing operating system. I dont think system would recognize the file. I have already run the iso with usb and disk without any luck.

 

[bigb123]

There should be an option "enable support for legacy devices" in bios settings. Try enabling it. Might detect your pd then.

This might help you.
http://www.sysads.co.uk/2014/05/install-winusb-ubuntu-14-04/

 

[destructor]

It is set to legacy. Shows up pendrive but ubuntu restarts

 

[bigb123]

It is set to legacy. Shows up pendrive but ubuntu restarts

follow the steps mentioned in the link i posted in my previous post.

 

[destructor]

I got the windows 7 setup file running from boot setp - cd rom and setup started.
Thank you all.