I had Windows 7 through Boot Camp on my 13" Macbook Pro but deleted it before installing Boot Camp drivers and software. However, after I deleted the entire Windows partition through Boot Camp on Mac, I get the weirdest error message that looks like it's from Windows. When I start my Mac, it says that there is "No bootable device found. Please insert boot disk and press any key." I got the computer to boot into Mac by holding the option key and selecting Macintosh HD, but I need to know how to remove the Microsoft boot manager (I assume that's what the message is) from my computer. Thank you.