Visit sometimes HiPath AP2620 website we recommend. It will help you to use your VAIO BZ570N02 hardware to the fullest SONY extent.
There, you can download the latest VAIO BZ570N02 updates of firm ware and HiPath AP2620 drivers for your KW811LA dc5800 device. You can also create GeForce GT220 restore points of your system in case of program failure. You would be able to retrieve initial state easily and try installing a VAIO BZ570N02 driver one more time. If you have an outdated KW811LA dc5800 unit, you won’t be able to find the matching VAIO BZ570N02 driver thereto.