IF you have just reinstalled the operating system it is unlikely in the extreme that the windows Operating system installation disc has/had the exactly correct specific driver for the WLAN (WiFi) card that is inside the laptop.
For that you must go to the website of the manufacturer that produced your Laptop/Notebook computer and download and install those drivers.
"Drivers" are the Software that allow your Operating system to control the various hardware components of the computer and they are one of the things overlooked by the home user when re-installing the the OS.
Does the WIRED internet work on the notebook after your re-installing the system?
Because quite often that will work off the driver that is included with the OS installer
and using the wired internet makes loading the other drivers directly to your notebook easier.
If the wired internet does not work I recommend downloading that driver to a USB "thumb drive"
and installing that driver first...
I've had some issues on some computers (my old Gateway M350 (c.2004) will get smashed
with an axe before I do it again) in the getting the WiFi/Network to talk to the browser software
for the first time even with the correct drivers installed.
Typically a flash card will not work for this because the card reader requires a driver,
Often there is a default setting in Bios/CMOS that gets reset with an OS re-install that you have to go through bos setup and turn the WiFi back on.
I know I went absolutely nutz turning on the media card reader on a few HP nc6220 notebooks
because the control for that as burried three menus back under "Device security"
most computers these days have USB support native to the computer's BIOS, so
those work independent of the OS & Drivers
If you tell me/us as much detail about the hardware as you know
it'll make it a lot easier to help you find exactly what you need
but above all if you start to get frustrated? walk away... just walk away.
And come back to it when you aren't frustrated.