Reset to factory settings

I recently purchased a MBP for my daughter who's going to college and she left me her old Macbook that is working fine but I want to reset it to factory standard to give it to my wife to use, I do not have any disc to be able to reset it with it, please help.
THANKS
CARLOS

We need to know which version of OS X it's currently running. And give us the specs for the MacBook while you're at it. Year and model.

Click on the Apple menu at the top left of the screen. Select "About this Mac".

OS Version 10.6
Macbook 3.1
Intel core 2 Duo
2 GHz
1GB
I couldn't find the year

Just download AppCleaner and use it to uninstall any third party software you don't want it to keep and backup any files your daughter has not kept a copy of

Then Create a new admin User in System Preferences > Users for your wife

Restart and login to the new admin User account

Go to System Preferences > Users and delete the old User account

Now you have a blank Mac with a fresh User account without the hassle of reformatting

OK, that's good. However, you're going to need an install recovery disk in order to wipe the drive clean and reinstall the operating system and applications.

Give Apple customer service a call and ask them to send you a retail version of Snow Leopard. (OS X 10.6) It will cost $29.99 plus a small cost for shipping. When you receive the Snow Leopard disk (DVD) boot the MacBook with it and use Disk Utility from Utilities to erase the hard drive. Format the hard drive and continue to install Snow Leopard and applications from the disk.

If you have any questions when you receive the disk, post back to this same thread. (You can subscribe to this thread and it will be easy to find later.)

I'll give it a try and I'll let you all know the outcome
THANKS
CARLOS

where can I get the AppCleaner, I've search in the App store and nothing came up

You can get "appcleaner" from here.

One note: Be careful using the method described above when creating a new user. If you're familiar with Mac OS X and user accounts, go ahead and do that instead. But if you want a clean start, it's best to use the format method.

In any event you're going to need a startup and recovery disk for any future trouble shooting. So go ahead and order the Snow Leopard disk from Apple even if you decide not to use it.

Thanks
very smart choice