Download Android KitKat 4.4.4 stock firmware for Vido W8C / YuanDao W8C tablet from here or from here. Download previous firmware version from here. Download another Yuandao firmware from here.
Archive： W8Cziyouguang_android_4.4_dous os_20150204-ZS
Model： Vido W8C / YuanDao W8C tablet
Image file size: 465 MB
Platform: Intel Atom Z3735F
Build number: inet_w_32-userdebug 4.4.4 KTU84P eng.inet_rance.20150204.101014 dev-keys
Caution: Please do not update firmware unless you know what you are doing, you really want it or it is absolutely necessary. Firmware updates may occasionally have bad results, like bricking your device, temporarily or permanently. The firmware update process is done entirely at your own risk. Before attempting to update the firmware, back up your data.