A few (4?) years ago I bought a Asus K53SJ-SX216V notebook which has a card-reader from Realtek. This card-reader is used in many notebooks from Asus and other brands. Unfortunately the driver of this card-reader is not automatically installed for Windows 8.1 and I didn't get the right results at the first search attempt on the internet. Hereby some simple instructions to install the driver for Windows 7, 8 and 8.1.
The card-reader is visible in the device manager of Windows by the name "USB2.0-CRW". This is the Realtek card-reader device.
The right drivers for this device can be found on the site of ASUS and you can download them here. Notice that this driver is originally for Windows 7. However it will also work for the newer versions of Windows. Both 32 and 64 bit.
Just extract the folder. Run the "setup.exe" executable and follow the instructions. Reboot and enjoy the fully working card-reader.