ssherjj Sysnative StaffMicrosoft MVPContributor Joined Sep 28, 2017 Posts 336 Location New York Aug 29, 2018 #1 Help please...I have an old 2008 Gateway desktop computer that is running pretty good. I have 2 500GB hard drives. Disk 0 has Windows 8.1 Pro N installed on it for many years. I installed Windows 10 Pro on the 2nd Partition. When my system boots up I get an option to Boot from 1- Windows 10, 2- Windows 8.1. As I boot up I click on Windows 8.1 and then the computer restarts and is Stuck in Windows Automatic Repair loop. I have tried resetting with Media DVD but it will not accept any of my Windows OS's. I am not really familiar with the Command Prompts that I can use?. In Disk Management I see the C drive and D drive when I am in Windows 10. I cannot format Disk 0. Both drives are Primary Partitions. It's been 5 years since I have had this dual setup and sadly have to say I have forgotten alot of things. It is confusing when Disk 0 is the D drive. Please let me know what you need from me or any advise is appreciated...no hurry for I cannot get to my Gateway Computer today. :banghead: Thank you!