I want to reset my macbook pro to its factory settings but i don't have the disk. My macbook pro has OX Lion and intel core i5. How do you reset it without using the disk?

I want to reset my macbook pro to its factory settings but i don't have the disk. My macbook pro has OX Lion and intel core i5. How do you reset it without using the disk?

For OS 10.7....
-- Restart holding command (?) and the R key for 45 seconds.
-- Coose "Disk Utility".
-- Erase.
-- Quit Disk Utility.
-- Choose "Reinstall Mac OS X".

For OS 10.6.8 or earlier....
You cannot add any apps or any OS to an empty HDD without some DVD or other HDD that has that stuff on it. You can't get software out of thin air.

You can create a new user and delete the old user. That's as close as you will get. so....
[All typing commands that follow require strict adherence to the exact spelling. This includes noticing where there is a space between characters and where there is no space.]

Boot to single-user mode (hold ? and the S key for 45 seconds at startup).
Type:
/sbin/mount -uw /
Press Return.

{Nothing appears to happen, no problem.}

Type:
rm /var/db/.applesetupdone
Press Return.

Type:
reboot
Press Return.

{Now stuff appears to happen.}

Setup Assistant appears. Create a new account, but be sure to choose a different short name than that of the original [[short name is the name of the user account folder]]. Then open System Preferences > Accounts. Select the old account, and delete it (the - sign).

Restart the Mac
Hold down command + s after the chime.
The terminal should show, at the terminal prompt enter the following: (Hitting enter after each line.)

mount -uw /
rm /var/db/.AppleSetupDone
shutdown -h now

just insert the disk and it'll go step by step for ya.