Any device that connects to the computer, such as a printer, scanner, monitor, keyboard or mouse.
Dave should check to see if his daughter's dorm has a printer. Sometimes schools will have printers available on the wireless network already. If she still needs a printer, then Leo recommends the Canon Pixma. It's easy to set up, and capable of printing over Wi-Fi. There is a chance that the school won't let her connect the printer to their Wi-Fi, though, and the advantage of wireless is lost when she's going to have it right next to her computer anyway.
Leo's not a big fan of HP printers. They're cheap printers, but they really get people on the ink. Leo would get an inexpensive laser printer because the cost per page is much lower. It won't print color as well though, and certainly won't do photos, but will be fine for charts and some presentations. Leo prefers the Epson Workforce All in One printers. Canon makes some decent ones as well.
Since the USB port on Elias's computer works for other devices, and the Belkin NIC (Network Interface Controller) card works on other computers, Leo thinks his problem is with drivers. When installing devices via USB, it's important to not plug the device in until the drivers have been installed. Elias did this correctly, though. Belkin support suggested that it could be a firewall preventing the card from accessing the internet, but Leo doesn't think this is likely. Elias should make sure he has all of the latest drivers for the correct model.
No, the USB is not for connecting to the TV. That's for viewing photos from a USB thumb drive. She'll need an HDMI connection, but her Dell Latitude doesn't have an HDMI out. Many laptops will have VGA out, and it's possible that her TV has a VGA input. This would work, but it isn't the best way to connect it because it's analog, not digital. Her laptop does have DisplayPort for video, though.