Re: can I install windows on Macbook pro OS X Yosemite?
I installed Windows 7 and then Windows 8 on a Macbook Air running OSX Mavericks. (I've since made that laptop OSX only, after running it as a dual-boot OSX/Linux Mint machine.)
It went very easily. The partition of my SSD took seconds. Will it be the same for an old-fashioned hard drive? Unknown.
Just make sure you have a USB key that's at least 8 GB.
Even if you have a CD version of Windows, Bootcamp will create a bootable USB for installation.