The upgrade went perfectly smooth up until the License Terms screen appeared. I had no way to click on "Agree" because the OS would not accept any input. My keyboard and mouse appeared dead. I tried all the other USB ports and the mini 6-pin mouse socket. After I rebooted and Windows 8 Pro restored a banner appeared with: Couldn't update to Windows 8.1 Preview Sorry, we couldn't complete the update to Windows 8.1 Preview. We've restored your previous version of Windows to this PC. 0xC1900101 - 0x40019 I've attached C:\$Windows.~BT\Sources\Panther\setuperr.log It's gibberish to me. Any ideas? System stats. OS: Windows 8 Pro with Media Center CPU: Intel i7-965 MB: Asus Rampage II Extreme GFX: Gigabyte GTX 590 Storage: 3xWD 640GB (RAID 0) All windows updates applied.