Will my macbook reinstall original os or the updated os

Question

ok so this is whats going on and sorry if this has been covered somewhere,I'm new to apple products and how everything works in regards to reinstalling.
I'm going to be selling my macbook pro.
I have found clear and understandable instructions on how to back up,log out and delete everything and then finally reinstalling.
BUT I am a little confused with 1 thing......
my computer was bought with mountain lion pre-installed and no disks.I have since upgraded to Mavericks
when I go to reinstall.....will it automatically reinstall mountain lion or will ask me to log in so it can reinstall Mavericks?
I don't want to have to reinstall with my apple ID cause then the person who buys my computer will be s.o.l. but I also am not about to do anything illegal.
thanks for the help

Answer 1

What you should do is deliver the computer with a fully repartitioned and erased drive. The purchaser can then use Internet Recovery to install OS X. That should use the purchaser's Apple ID to install OS X. You need to remove the computer from your registered products: Your Support Profile for Registered Purchases. This allows him/her to add it to their registered products and associate the machine to their Apple ID.
Or you can do the above, partially, by reinstalling OS X but shutting it down after the installation is completed but before it reboots:
Install Mavericks, Lion/Mountain Lion Using Internet Recovery
Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.
Boot to the Internet Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND-OPTION- R keys until a globe appears on the screen. Wait patiently - 15-20 minutes - until the Recovery main menu appears.
Partition and Format the hard drive:
Select Disk Utility from the main menu and click on the Continue button.
After DU loads select your newly installed hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed. Quit DU and return to the main menu.
Reinstall Lion/Mountain Lion. Mavericks: Select Reinstall Lion/Mountain Lion, Mavericks and click on the Install button. Be sure to select the correct drive to use if you have more than one.
Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.
This should restore the version of OS X originally pre-installed on the computer.