Dylan likes to play video games, and his new laptop has a broken keyboard. Leo says that sounds like a factory defect that needs to be addressed by the manufacturer. Dylan can plug a USB keyboard into it in the short term, and it will replace the keyboard on the laptop. Dylan tried that, and that's when the keyboard stopped working. Leo says that it sounds like the laptop keyboard got disabled in Windows. He recommends going into device manager (Windows Key + X, device manager). Look for the keyboards section and make sure your standard keyboard hasn't been disabled. He may have also hit a function key that disabled the keyboard. If Dylan has a touchscreen laptop, booting into tablet mode and then that will give you access to the on-screen keyboard, and from there, you can make changes to re-enable the keyboard. Laptops that don't have touchscreen can use the mouse to click into the Windows Ease of Use setting to enable Dylan to type with his mouse on the virtual keyboard.
But the keyboard may also be disabled in the SETUP or BIOS. So go into your BIOS settings and see if it has been disabled on a more basic level. It may also be a good idea to look online for an updated keyboard driver. You can also remove the older driver and then reboot. It'll reinstall. Here's also a technote on how to fix keyboard problems here. But what Leo suspects is that Windows has installed a new driver, and there's some sort of confusion. Deleting the device driver and rebooting will prompt Windows to install the right driver. More here.
Another possibility is that Dylan's mom's keyboard is wireless, and removing the wireless USB dongle will fix it.