So I am running on Maverick on my primary Macbook Pro drive and put Yosemite on a external hard drive. I later deleted the Yosemite from the external hard drive by reformatting it. However when I boot up my Macbook Pro it does't give me the original grey to apple boot up. Anytime I turn on my Macbook a black screen pops up first then the grey background with Apple logo pops up. Also anytime I hold down the "Option" key during boot up it'll go from the black screen to my hard drive and recovery startup and that also has a black background. When I click select network it also has the Yosemite UI and not the Mavericks. How do I fix this? I don't like Yosemite at all.