Firstly, can you make sure that your wifi is actually enabled? I've seen some people forget to enable their wifi before.
To get the network adapter driver, go to the start menu, type in "device manager" in the search bar, run it, go under network adapter, and copy down the model of your network adapter. After you do this, download the driver software on whatever computer you are on now, and transfer it over onto your laptop.
Support page for Driver for the HP 655 laptop. You just select the correct OS (Win 7 32bit or 64bit, in your case) and scroll down to the correct driver that you want. You will need to put the driver onto a Flash drive or possibly an external HD and move over to your laptop.
P.S. It's more than likely that Windows 7 already has a WiFi driver for you computer and might just need enabled, but I have the links above in the case that you don't have the drivers.