My computer is connected to a LAN and works at ~22 Mbps. Lately I installed an old computer for my grandson. But this one had no internal network card, and as didn’t want to open the computer and dabble inside I bought and installed a USB WLAN L100 network card. However this reduced the speed on this computer to ~4 Mbps. Does the USB connection reduces the speed or can it be the card’s fault? And if so, what how to chose an appropriate USB card. It will be connected by wire to a ZyXEL router.