Good day everyone. Im in need of your expertise to install a mac os x in a MBA 13". Im a newbie to mac btw. Just recently bought a used MBA 13 2009 mac OS Lion Here is my problem. I wanted to reset the os to factory settings but i mistakenly erased/cleared the hard disk which the OS is in. I failed to make a copy or back-up. So, i dont have an existing OS running. I tried to reinstall lion via the internet recovery but i end up with an error that the os is not available. i do have an apple ID but i was not able to download an os beforehand. so, i dont think i can use this option. Im left with the recovery utilities. whenever i try to boot, i can only see the recovery HD in the startup screen. i believe that the os installer and the hardisk icons should be seen also if i insert the bootable usb and the empty hardisk too(mackintosh HD) I downloaded the DMG file of Mac OS Yosemite from getintopc.com it was noted the the file is for 32 and 64 bit windows. does it mean that the os is for windows use only? like the hackintosh or dual boot system. do you happen to know any reliable site where i can download a legit DMG file or what specific DMG file do i need to download? the retail one? the one from app store? there are many in the torrent sites. i cant figure what to download. I tried to make a bootable usb using transmac in my Windows xp laptop but will not boot when i plug it in my MBA. also, it took me 6-8 hours just to write the os in the disk. any other alternative app? or maybe my DMG file is corrupted. can i use ISO file of the Yosemite to boot from the macbook? i just want to make a usb bootable mac os x(any os) using my windows xp since im not able to use my MBA how to properly prepare my hard disk for usb bootable mac os install? do i need to 2 partition? i cant seem to partition it properly. i stumble the error. "partion failed, couldnt unmount disk" im sorry for all the questions but im so desperate right now. please help me and would appreciate any guides.