Bobby, if you don't want to reinstall the OS, but want to reset it to a "factory fresh state," you can use the following info that I just used about 2 hours ago to reset a Snow Leopard computer I didn't have the OS disk for.
How to “reset” a Mac OS X installation
Here’s how to “reset” an installed Mac OS X and virtually return to a “virgin” state with a welcome screen prompting the user to setup and customize his Mac OS X installation:
1. Press Command-S during startup to get into single user mode
2. Check the filesystem:
# /sbin/fsck -fy
3. Mount the root partition as writable:
# /sbin/mount -uw /
4. Remove the hidden .AppleSetupDone file:
# rm /var/db/.AppleSetupDone
5. a) For Mac OS X 10.5 ‘Leopard’ and newer, do:
# launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist &
Repeat for every user previously defined on the machine (replace {username} with the real user name):
# dscl . -delete /Users/{username}
(optionally execute the next line, most people won't probably need it)
# dscl . -delete /Groups/admin GroupMembership {username}
5. b) For older versions of Mac OS X, do:
# rm -rf /var/db/netinfo/local.nidb
6. Remove the home directories of users. For every user do (replace {username} with the real user name):
# rm -rf /Users/{username}
7. If applicable, remove already created files in root’s home directory, e.g.
# rm /root/.bash_history
8. Reboot:
# reboot
You can also optionally remove the files in /Library/Preferences with:
# rm -R /Library/Preferences/
This could effect some third party apps installed.
Oh and it's useful to point out this method will not touch the installed OS, or installed Apps, just remove personal data, and reset the OS to a "welcome state."
Hope you find it useful, I've used it for ever Mac I've sold in the last 5 years.
-Cheule
