Why does cursor changes to arrow and typing stops

Question

When typing or attempting to type, the cursor drops from the end of the letter and turns into an arrow, which can appear anywhere on the screen.  I then have to move the mouse to the last place I typed.  Have restarted and shut down computer several times.  No change.  How do I fix this?

Answer 1

I DID get the 'middle pane' - which I am very used to seeing and, as always, unchecked the box to receive the unwanted programs (I already have Google Chrome AND an excellent anti-virus program - thanks all the same!).
But it then went on to offer me additional programs. I did not take any screenshots as I was not expecting all this palaver. And I don't remember what the programs were that I was offered either. I just wanted to get on with the download and get on with my business. I was getting very frustrated though. As I said earlier, underneath the small dialog window which was offering these programs (and which, if I remember aright, was inside the main window) - the "Accept" and "Decline" buttons were still visible BUT it looked as if the "Accept" button was the only active one (being highlighted) whereas the "Decline" button was greyed out. And, as I said before, it 'looked' as if one needed to click the "Accept" button to agree to the Conditions of downloading (which is quite normal, as you know).
But being of a wary nature and hopefully not as gullible as some, I tentatively clicked on the "Decline" button anyway - and it worked. The offer of those one or two extra programs was then replaced by one or two more - in the same type of small window. Having learned my lesson, I continued to decline and eventually got to the end. But this experience did make me feel most irritated, as I indicated in my original post. It should not be necessary to be expected to jump through all these misleading hoops just to update an every day program, should it?