The first step is knowing exactly what hardware you are dealing with. On Windows, if you have no internet, you can open Device Manager (right-click the Start button and select it). Look for a section often labeled "Other devices" or "Network adapters." An entry with a yellow exclamation mark is your culprit. Right-click it, select Properties , then the Details tab, and switch the property dropdown to Hardware IDs . This cryptic string (something like PCI\VEN_8086... ) is your golden ticket.
With no internet on the target machine, you need a second device—a phone, a tablet, or another computer. Search for the Hardware ID or the laptop model number on the second device. Navigate to the manufacturer’s official website (HP, Dell, Lenovo, Intel, Realtek, etc.) and download the driver file. install wifi drivers