I always edit cells via the formula bar, not directly in the cell. For some reason the appearance of the cursor has suddenly changed from a thin vertical line to a much thicker one, which is unhelpful and distracting.

When the formula bar is first opened for entry or editing the cursor appears as the normal thin line, and remains thus if the cursor is moved either by mouse or arrow keys:

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Name:	Excel cursor normal.PNG 
Views:	6 
Size:	2.6 KB 
ID:	2020

But as soon as any other key is pressed to begin entry or editing it changes to the thicker line:

Click image for larger version. 

Name:	Excel cursor wide.PNG 
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Size:	2.6 KB 
ID:	2022

As you can see, it's similar to when the Insert keyboard function is selected (but that's not the case). This is occurring in all but one of my workbooks, including one that I'd not opened for several months.

Can anyone please tell me how to remedy this annoying behaviour? And preferably how it might have occurred in the first place.

Many thanks,