If your laptop is HP, they won't have second partition for you even your hard drive is over 160GB.
HP should have a recover disk(s) image which is in your computer. Usually the user's manual said, make a recover CD(s) when the first time you use this computer. When you turn on your computer, look at the monitor screen careful, they should tell you which key you can reinstall your computer.... such as 'F2 - recover system' message.
If you totally lost all the recover disk in your computer. You have to buy one set from web or call their help line-- provide all the necessary information with your computer. (this is happend to one of my friend, it take around 1 week you get the Recover CD).
Good Luck....