Hi, I own Macbook from 2010 [ it was my uncle ]. Recently I tried to re-install the OS [ Lion ]. I did it from "Recovery HD" by erasing the hard drive first and then going to re-install os x from recovery hd. Then I prompted to enter my appstore login details in order to download the OS. But I don't have the appstore login details used on this macbook so I cannot install it from recovery HD. I tried to enter another appstore account but it says "This item is not available right now" [ I think I need to buy it or something ]. So I tried to download yosemith or mavericks a free OS to install. Version: 10.10.4 yosemite I burned it on usb and made it Bootable with some tutorials but none of them worked. When I plug the usb and press "Alt" to get the boot options popup when I start my Mac, I do see the USB but it shows the question mark icon that says it doesnt recognize a boot able device. I'm pretty stuck here because I don't have any other solution.. I tried to purchase a new Lion license but I'm from israel and they only sell it online to united states. Thank you for the help!