network upgradation of ubuntu-8.04

[prudra]

I have pre-installed ubuntu-8.04 on my netbook with bios-access password locked and the password is unavailable to me. I want to ubgrade OS to a higher version of ubuntu. Since the bios-access is locked I am unable to use installation-usb. Is upgradation possible via broadband network and how? Help will be highy appreciated.
Thanks.
P.Rudra.