So a couple weeks ago I installed a 240gb SanDisk SSD in my desktop and set Windows to boot from that drive. I set my 1tb HDD as a secondary device and wiped Windows from it, just so I have most things boot from there. Now all of a sudden, my computer doesn't like my HDD anymore. The computer recognizes it in file explorer as well as the BIOS and Disk Management, however when I attempt to make the drive active, the option is grayed out. I attempted to make this drive active through CMD and got the response "The selected disk is not a fixed MBR disk. The ACTIVE command can only be used on fixed MBR disks. I'm not entirely sure why the computer stopped using this disk as primary, but if anyone can assist me on this issue, I would appreciate it.