Originally Posted by McSteel
Probably best to use specialized software for it, Paragon's Hard Disk Manager works great for this purpose.
You could possibly do it with the tools Windows already has, but then it'd be more work than actually installing from scratch.
It was really easy. I just installed Hard disk manager 2015, then i selected "convert gpt to mbr", and i also marked the partition on which windows is installed as the active partition, and i clicked apply. It restarted my system and it made the changes, then i disabled EFI(2.2tb infinity from MSI) and i booted in windows. I then put windows to boot into safe mode and i changed the controller from IDE mode to AHCI, then i booted into safe mode and rebooted into normal mode. I am now using windows without EFI and AHCI mode enabled.
Thanks for telling me about Paragon Hard Disk Manager
And about reinstalling from scratch...i really hate doing it, since this is my audio rendering machine, and when i reinstall windows i have to install all my VSTS and music software...so it's best to avoid that.