Yes, your Mac is dual-booted with Windows already set up.
Yes, your Mac is dual-booted with Windows already set up.
You can dual boot Mac without installing it. Just install Windows alongside your Mac and choose which one you want to use at startup.
Are you planning to set up Mac OS X on your computer? If yes, then proceed. You can use iBoot for Snow Leopard or UniBeast for Yosemite. Visit the site at http://www.tonymacx86.com/. It will install its own boot loader (possibly Chameleon) to choose the operating system you want to start with.
Be honest, just proceed without hesitation. If needed, format the partition—use a spare drive if available. I own a low-quality 80GB Barracuda perfect for testing; it’s simple to format the entire drive, and you won’t worry about accidentally deleting the wrong one.
It’s likely you’ll face issues if you attempt to install OS X on a drive that already has Windows installed. I’d suggest clearing the drive and beginning fresh with OS X.