I have an used MacBook with OSX Lion on it. I am very new in using this Apple product. Few days ago, it deplorable crashed after I installed Wireshark and started to use it for 2-3 hours. After a hard reboot of the Mac, it get stuck loading something, between password screen and system start!? So I decided to take a new step in learning OSX and tried to reinstall it. The recovery software asked me about Apple ID, and told me that I can easily create one, so I created one. After that, told me that the MacBook isn't registered into my Apple ID account, so I have tried to register. The registration form ask me about serial number and told me where can be located: Product Packaging Label About this Mac Apple System Profiler On the base of the computer or other hardware Inside the disc drive door I wasn't the first owner of this machine, it was bought on the second-hand market... so I don't know any details about it. Obviously, I haven't packaging label and because the OSX isn't working anymore I can't check the menu about this Mac... no Finder, no Dock or any hardware overview. Also, on the base of the MacBook isn't the serial number and the disc drive have no door! So, I have searched on internet (using my PC with Linux) and found that I can use this command to get the serial number! ioreg -l | grep IOPlatformSerialNumber Wonderful! But now, I get a different message from Apple, that my Apple ID didn't purchased Lion. Of course, it is a new one you stupid, I just created in order to reinstall... the OSX Lion is already in the machine, just don't work! On the other hand, I have no special interest in Lion or another kind of animal. As long as Apple sells all their products with some OSX already installed, I don't care which one it will be reinstalled. I have the machine, so I must have the right to use it somehow. It is presumed that this Macs are easy to use, but I lost already 5 days trying to reinstall the OSX. For Windows or Linux take only half an hour. Please, can anybody tell me which is the way to perform a SIMPLE reinstall of the OSX into a MacBook? What can I do to reinstall the original software on this machine? I tried to pray but it does not work!