Apples use another bios system (well written up on the web) so no one can take any of the Microsoft issued Windows CD/DVDs and boot that. And if your plan was to install MAC OS X there are tomes on the web about which version runs on your Mid 2011 model (that's not enough for me to nail it for you.)
1. Identify your Apple -> http://support.apple.com/en-us/HT201300
Notice there was no Mid 2011?
2. Another primer at -> https://discussions.apple.com/docs/DOC-6413
Bob
PS. Apple OS X wasn't a download for many models. Some folk hunt for that for months. I don't want to lose time like that so I identify the machine, then hunt down a good copy (even if I have to pay up.)
Bob
I bought a macbook pro Mid 2011 and the guy told me it had windows on it. I'm decent with computers so I figured I could just make a bootable dvd form an iso and viola i'm done and running os x. Instead i'm having some issues that I hope someone can help me with.
1. When I press my power button I hear the chime but it goes to a grey screen (no apple logo). After that it goes into a black screen with a blinking cursor and then it loads windows. None of the commands work (Command + Option + R + P or just Option, or C to boot from a dvd) nothing works.
2. How can I download Mavericks onto a usb drive and install it on this machine? I do not have any other macs.
If anyone can please help me I would be forever grateful. Thank you.

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