I just got a MacBook Pro used. The person said the harddrive crashed and they replaced it but had not installed the OS yet, but had the disc. so I bought it on good faith. Well I tried to installed the OS, by pressing'holding C key at startup with the disc in. it does nothing except spin the disc for a few seconds then you can hear the disc drive clicking, like it's not reading the disc. Then the folder (?) starts flashing on the screen. I tried to open the Disc Manager by pressing OPTION at startup but all it does is bring up the Open Firmware Lockscreen, same thing happens when I push Command R at startup. I have tried to reset this password via information that I found on here with resetting the PRAM (holding CMD, OPT, P R for 3 full restarts) and that did nothing. Right not I have no clue what else to do to get the OS X Installed. Any suggestions?