If you successfully install the driver, the driver is installed on `/lib/modules/<linux version>/kernel/drivers/net/wireless/realtek/rtl8xxxu`. Check the driver with the `ls` command:
If you successfully install the driver, the driver is installed on `/lib/modules/<linux version>/kernel/drivers/net/wireless/realtek/rtl8821cu`. Check the driver with the `ls` command:
```
ls /lib/modules/$(uname -r)/kernel/drivers/net/wireless/realtek/rtl8xxxu
ls /lib/modules/$(uname -r)/kernel/drivers/net/wireless/realtek/rtl8821cu
```
Make sure `8821cu.ko` file present on that directory