And you'll also risk infecting that computer as well
.
I'm personally skeptical about OP even having a virus. Just seems pretty shady to me, "family member used a computer and downloaded a virus", yeah right, would probably help asking them first what they actually did? And to all people suggesting fixes within windows, as I understood it, the OP isn't even getting inside windows at the moment. Are you getting the window that has "Launch Startup Repair (recommended)" and "Start windows normally" options when you boot up? Might be a hardware failure instead of virus.