When running Avast on full Win 8.1 in desktop mode on a 7" tablet, the UI can't be closed.
The width of the Avast UI means that it goes off screen to the right on thinner tablets in portrait mode, however when you drag the window left to expose the close, minimise buttons you find the UI has clipped itself to fit the screen so the buttons are not visible. It will no longer allow you to drag the corner to open up the UI so you cannot close the app.
This is exacerbated by the fact that the UI does away with the old top left icon in a drag bar that all windows used to have. This icon could be double-clicked upon to close a window (a left-over from Windows 3.1).
This is a problem on Windows tablet that is locked in portrait mode due to the type of apps that are being run on it. We have locked tablets that are designed to be used in portrait mode and are locked in that state. The only way I have found of closing the Avast UI when it's buttons are obscured (so far) is to uninstall it.
