Hello - I am trying to do a clean install of Win 7 Ultimate on a ThinkPad W550s. It originally came with Win10 on an SSD but the drive was so full of malware rootkits and viruses that I dared not use it. I would clean it and most would come right back. So I wiped the entire drive hoping to do a clean install. The first error message I got was that the OS could not be installed on a GPT . So I decided to install Win 7 Ultimate, which is what I originally intended for the drive. That gave an error saying that the drivers for the USB DVD drive were missing!
Can anyone give me step by step instructions for installing Windows 7 Ultimate X64 on this W550s?