If the current driver is broken:
The Realtek 8811CU chipset supports the 802.11ac standard, delivering speeds up to 433 Mbps on the 5 GHz band and 150 Mbps on the 2.4 GHz band. Outdated or generic drivers can severely throttle this performance. Updating your device drivers provides several key benefits: realtek 8811cu wireless lan 80211ac usb nic update portable