The first and most reliable source for drivers is the hardware manufacturer's website. For Broadcom, you would visit the Broadcom website . However, Broadcom's support page might redirect you to the specific company's support page that produced the device (like Dell, HP, etc.) if it's not a direct consumer product.
If you experience issues during or after installing the driver, try the following troubleshooting tips: broadcom 80211n network adapter driver windows 7 64 bit 11
: If Windows does not recognize the device, use the "Browse my computer for driver software" option in Device Manager to point directly to extracted driver files. The first and most reliable source for drivers
If your manufacturer does not support Windows 7 anymore, you can try a generic driver. you can try a generic driver.