You might want to update the Wi-Fi adapter's driver to the latest one by dowloading it from the Manufacturer's site, it might help.
Also, please install and run Xirrus Wi-Fi Inspector
from your Dad's laptop. Double click the Xirrus Icon on his laptop's desktop, Tap the Printscreen key on your keyboard, open up Paint then choose Edit from the Menu and select Paste, then SAVE it. Upload and attached the file here.