I have an efi-based 64 bit system with win 8 pre-installed. I want to downgrade to 32-bit win 7 and so I booted up a bootable win 7 usb and opened command-prompt with shift+f10. I used convert mbr command on disk 0 (which should be gpt) and it says: "the specified disk is not convertible. cdroms and dvds are examples of disks that are not convertible"
Now, I have not cleaned the disk yet, so this might explain the error. However, I would think a different error message would appear if that were the case and I don't want a laptop without an os. Furthermore, I cannot enter "Repair your computer" as it said system recovery options was incompatible. What is going on here? i definitely want to convert to mbr for other reasons too.