How to fix system update error?

I updated my Lenovo A328, after downloading and installing its update, it showed a list of options, I was trying to go to "Reboot System Now" when I pushed the volume down button. and then shows "Now place update file...adb <filename>...." and it doesn't work anymore. I tried to restart it but the power button didn't work, so I took the battery off and put it back on. Still it only showed Lenovo logo and the Android logo. Please Help.