Restore to Original Factory Settings

I am at my wits end.  I have been looking all over the internet and on Dell for the past 2 hours trying to find help with no luck.  I have a Dell Inspiron E1505.  I want to wipe everything off this laptop except what was on it when I purchased it.  I keep reading hit F12 or control F11 and then click Restore.  There is no Restore anywhere.  I have searched and searched and I can't find anything.  I have found that a lot of other people don't have that option either.  Please help!

Thanks!