A new drive runs between 60 USD and up though normally between 60 USD and say 150 USD for a standard drive you see in laptops. The issue then becomes do you have any Windows Installation Media or the installer disks from your laptop upon purchase? If not I can give you legitimate, clean download links for Windows 7 (just need to know your version specifically) and then you can use the key on the bottom of your laptop to activate it.
Please let me know if it is truly frozen and about the warranty in your next reply. Then we'll go from there!