Can't run Windows 8.1 anymore

[DemonicLink]

Instead of saying a lot of things I will post the log and a screenshot of the error I get with a little of background.

I was running Windows 8.1 on the VBox and then I had to upgrade Windows 8.1 in the VBox (the new update that solved a HUGE security issue with a lot of Windows versions) and Avast antivirus, all this inside the VBox, I restarted the VBox and got inside again to start working but then I also had to update Avast outside the VBox, in my host and restart too, I turned off the VBox in the normal way and then restarted my host machine, when I wanted to start VBox again I couldn't anymore and I get the following error:

error.jpg (29.92 KiB) Viewed 600 times

Here is the log too:

VBox.log

(2.38 KiB) Downloaded 5 times

[frank]

There should be also a VBoxStartup.log file. Please attach this file as well.