I am using a Dell Inspiron 15R 7520 SE laptop which came with Windows 7 64-bit Home Premium. I followed these links to install Ubuntu 12.04 LTS in dual boot configuration :
I also used Easy BCD so that whenever my laptop would start, the Windows Boot Loader would ask me to choose whether i wanted to boot into Windows 7 or Ubuntu. Worked fine.
How do I upgrade to Windows 8 in Custom Install mode where all my Windows 7 Data will vanish, without affecting Ubuntu and the Dual boot settings?
I first tried on my own and ended up messing my laptop quite a bit.