All WiFi Connections Suddenly Lost

I upgraded to Windows 10 from 7 a few months ago, but unlike other users with this problem, my wifi started working perfectly fine. This was still the case this morning, but after I came out the shower, suddenly all my wifi connections were lost. It's a similar situation to that described here: [URL] ...., except obviously it didn't occur right after the upgrade. It's annoying that I missed exactly what happened, but oh well.
 
I have tried seemingly everything, including endless restarts and resetting the router, and I know it's definitely not a problem with the wifi since I'm typing this on another device on exactly the same network. One of the solutions I found was to go to the Power Management tab in configurations of the wireless device, and uncheck "allow the computer to turn this off to save power" - I found it was checked, so I unchecked it, but it still hasn't made any difference.
 
Initially, the wifi icon changed to an unplugged symbol with a yellow exclamation mark, but after uninstalling Hamachi, it's changed to the usual icon you get when wifi connections are available (wifi symbol with asterisk). However, the problem's been exactly the same. I have a Dell Studio 1555, which admittedly is quite an old machine, but it was fine until now.