After upgrading to 21H2 version of windows 10 or upgrading PC to windows 11, unfortunately WiFi may have been disabled. If you connect to with external wifi adapter it may be on disruptive connection.

This problem arises either for adapter driver, which not updated with OS, or the adapter disabled when system updated or upgraded.

To solve this problem, first try to update wifi adapter driver. To do this go to start menu, search for device manager, expand Network Adapters, click right side on the wifi driver and select update.

If not update or doesn’t solved the problem, then go to settings, then Troubleshoot, then Other troubleshooters option.

Then run the Network Adapter. You will have a list of all network adapter, select the wifi, then click next.

You may have this issue that adapter is disabled. run troubleshoot as administrator, It may solve your problem. At least I have the solution on the process.

If you can't find the inbuilt wifi adapter, connect a usb wifi adapter. Then you should have find the builtin adapter. Now run the troubleshoot.

Another option can be reset network. Go to settings, Network & internet, Advanced network settings, Network reset. Click on Reset now.

When all of those options failed, reinstall appropriate wifi driver for your PC.