I recently built a new computer and had to take a old hard drive out of another system...this system had windows 7 on it...when i went to boot up it would say "starting windows" then i would see 2 little orbs appear. It would then go on to tell me that i needed to repair my windows 7 files...it did that to no avail.
I do not have a CD/DVD drive in my system at the moment because I do not have enough 4-pin molex connectors (had to use an adapter for my GTX 460, getting new psu soon)
I was told to install Ubuntu onto a flash drive and boot from it...I did and it worked but now I want to get windows 7 back...I have it saved as an .iso on my computers other hard drive and i want to put that onto my flash drive...
Moral of this story is that you need to unplug something that's using a molex connector that's not essential to the operation of the computer. A case fan, an extra hard drive (assuming you're not using a RAID), something like that. Plug in your CD drive to get the thing running again and succeed at life