Behave? Who doesnt have access to a dvd drive these days?! Jeesus get with the times boyo.
Erm the only other way you could do it is download the ISO file get magic disk/mount then mount the iso file to a virtual dvd drive and then install it that way, looks like your only option thus is not recommended though personaly i would have borrowed someones laptop n copyed it onto dvd useing disk cleaner before installing windows 7.