I literally just finished building a computer and I went to into the BIOS to change the boot order so that USB hard disk is first. I then insert my USB and reboot. Upon rebooting with the inserted drive I get the "Invalid System Disk" error that tells me to replace the disk and reboot. This is the very first boot on the new computer. I had built a computer about 1 week prior and the computer booted up Windows just fine without any problems. This is only my second build (for a friend) and I don't know what to do to be able to boot Windows on to the computer. We cannot use a DVD as the build doesn't have one. Thanks.