Hello I'm new to the whole computer thing my brother gave me his old laptop and I want to restore it to its original factory state deletion of all files but my problem is that I don't have the windows xp disk so I can't re install windows xp how do I wipe all files while still keeping the current windows operating system on the computer thanks for your time

Well, you're going to make us ask, huh?

OK, what is the make and model # of the laptop? Most laptops have a recovery partition built into the laptop, unless a previous owner removed it.

On my laptop, pressing F11 (or maybe F10... Fsomething) tapping F11 when I first turn on the laptop brings up the Recovery Console and I can use the options in there to do a Factory Restore.

May not be relevant to your situation, but if System Restore is enabled on your computer, you may get some mileage out of it in this circumstance:

Windows XP System Restore Is Easy to Use

Another option is to just uninstall all applications you don't want and delete your brother's user profile (generally in C:\Documents and Settings). Not 100% factory clean, but a close second without further information on your setup.

System Restore only goes back a few months, probably not appropriate use for this OP's question.