Hi, I am just screwed up. I recently tried to install OS X Yosemite on my Vostro 3450. I formatted the recovery partition with hfs format and Did not install and then...... Boom I got non system disk error which probably means I corrupted the mbr of windows 7. I tried using windows 7 repair disk but it freezes at windows is loading files. I had only a Kali Linux live sub with me. With that I deleted Mac hfs partition and then rebooted everything went well but...... I did not get non system disk error yet there was a black screen with _ blinking and nothing happened. I have windows 10 preview working ISO files which can be burnt to DVDs using Linux live so is it ok to use bootrec.exe /fixmbr and fixboot and even rebuildmbr command. Or I have corrected mbr but I am in other problem and one more thing I have a13 bios with dynamic disk. Plzz tell me or I will get a sound thrashing.