How did you install win 7? If you used USB or DVD, that is going to be way to install the drivers again. You will need to download them from HP web site on another PC and copy them across.
You got past the main barrier that is just installing it in 1st place. Normally lack of USB 3 drivers is enough to stop some.
Another way is remove hdd, put it in another PC, copy drivers onto it, put hdd back in laptop again & install the drivers