After I successfully install Ubuntu using my flash drive and then reboot, my laptop forces me to choose my flash drive as the boot device. Otherwise it starts in Windows 7.
Also, when I choose the boot device, it starts the installation process again from the beginning.
My laptop is a Dell Inspiron 5520.
Edit: I checked the disk management and there are 3 primary partitions and 1 "OEM partition".
Did you create Live usb correctly? check out http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-windows to install the iso correctly in your USB.
also follow the following link on how to install a dual boot of windows and ubuntu: http://www.liberiangeek.net/2012/04/dual-boot-windows-7-and-ubuntu-12-04-precise-pangolin/ (refer the tutorial from ubuntu's installation images)
Before directly plunging into your installation via the USB, i would first suggest you to boot from the USB in Live mode once, just to make sure that everything is intact and the download of the iso was perfect. Doing this would check the USB for errors(if any) and will either won't boot properly in live mode or will not boot at all. I suggest you run in Live mode first.
Regards,WinuxUser
