Yes, it is in MBR format right now.
I did install using GPT at first, then it gave me that error I mentioned. Given I couldn't get on this site without a working installation of Windows, I just switched to MBR so I can at least use my computer.
Generic recap: With MBR I can only boot with the installation disc in the DVD drive, and with GPT that error won't let me install Windows.
Sorry if I wasn't expliciit enough in my descriptions and whatnot.