Lenovo Z580 laptop with W8.1. Unable to completely install updates. It appears to download and will restart but then we get the message that Windows unable to complete updates, undoing changes. We run malwarebytes and ccleaner. Windows Defender is the virus engine. We've done a System Restore but that didn't help either. We tried stopping and restarting Windows Update in the Services window. That did not solve the problem. One web answer suggests deleting the temporary window update files but we could not find those files or they were empty. There are about 12 important updates to be installed. Any suggestions are appreciated.