After turning Wi-Fi off and back on, it still didn't work. But, after a restart, it worked and I can see my wireless networks.

EDIT:
I'm still connected to my Wi-Fi network but it shows that icon instead of the full white bars.

I'm having an error where I couldn't open my wireless networks to select a network, but after reading online and going to services to check if something's enabled and on the right setting, I clicked...

I didn't install anything. It just appeared in the context menu when I shift + right-clicked on my desktop.
A temporary fix would be to type "cd Desktop", of course, "Desktop" can be changed to...