Sometimes the computer WiFi can't be turned on, maybe because you turned off the computer WiFi wireless switch. Here's my method to turn on the computer WiFi wireless switch for your reference.
For old computers, it will have a manual switch to turn on the WiFi wireless of the computer, which can be turned on.
For some computers, click windows + X, and a dialog box will appear. Click to open wireless.
For some computers, click FN + F5 or FN + F12.
Click the icon at the bottom right and select "all settings" menu, as shown in the figure.
Then select the "network and Internet" menu, as shown in the figure:
Then select the "WLAN" menu and click "on", as shown in the figure.
Then select a network and enter the password to connect.