Please provide make/model of your computer. Is it a desktop PC or laptop/tablet? Is it a self-built PC you built yourself? Or an OEM computer (Dell, Acer, HP, Toshiba)?
Laptops still come with a Wi-Fi switch, which often gets turned off if you remove it from your home and travel with it somewhere. The process of putting the laptop into a carrying case and then taking it out again multiple times can easily move the switch to the off position where you will disable your laptop's Wi-Fi and thus won't get any list of Wi-Fi networks to popup on your windows screen to connect to! Here's an example of what that switch looks like:
Other laptops, most modern ones have done away with that physical switch and use a keyboard combo...