Windows 7 Installation Driver/HDD Issue

Alrighty, I am helping my cousin fix his PC - He got some sort of virus. We were going to just format his HDD and reinstall Windows 7, like I've done before, after we booted from the disk, it said it could not find the drivers. We researched this, and we found making a USB installer got people past this error so we resorted to making a bootable installation USB drive( That got us past the driver error, but NOW when we are going into the custom setup, it isn't recognizing the HDD, so we can't format it in the setup. We also tried to do the upgrade option, where it puts all the contents into the a "Windows.old" folder, but it said that the installation started on a disk, and it wouldn't get past that... It'd be nice if anyone had any information on this problem.

Nevermind! We got it to work, we just plugged in a USB with generic mass storage device drivers. And it recognized it. o.o