Try downloading and installing the KitKat ROM via fastboot. You can find the file in https://developers.google.com/androi...mages#mantaray
, after you download you'll have to extract it and then you have two options to follow.
First things first, you'll have to copy the files that were extracted to a fastboot folder, or you can copy the fastboot.exe, AdbWinApi.dll, AdbWinUsbApi.dll and adb.exe to the folder where flash-all.bat folder is. Then you can execute the .bat by clicking on it twice, remember that you have to have your device on fastboot mode (press and hold both volume buttons then press power button). The only thing is that it will reset your device to stock, so all your data will be lost.
And the second option will save your data, you have to factory reset your device via recovery, then reboot in fastboot. You'll then extract the zip and get all .IMG files in the fastboot folder. Then you'll open a cmd in the folder and type the following:
fastboot flash system system.img
fastboot flash boot boot.img
This will reflash your device and you'll get to boot in KitKat stock
. Good luck, hope this saves your device
"Time is too short to cry, long enough to try." - March of Time (Helloween)
Sent from my KitKat Nexus 10