I bought the machine with no hard drive at all. Bought a new one and installed it. Machine is licensed for Win7 Pro and when I use my disk to start the installation, it gets to the screen where you select where you want to install the OS, but it shows none at all. I boot into the BIOS and I can definitely see the new Western Digital Hard Drive. I've been Googling for a couple of hours with no luck, so I'm hoping someone will have some guidance here. Thank you!