dragging a cell down to get a row count has been turned off

I am working with a friend who turned off the" I don't know the name of it" so I will try to explain.

In the past I was able to enter the number 1 in a cell and then drag that cell down the colum. The number would increase by one. it would enter 123... and i went down the coloum. This was good for finding how many rows I have.

He has turned off something now when I drag the cell down it copies what was in the cell above eg : I enter the number 1 in a cell and drag it down I get all 111111 all the way down.

So how to I turn this function on?

I have always found that, if you have two numbers in a sequence (e.g. 1 and 2) and you select them both, you can left click and drag and the number will increment.

With one number, you can use press Ctrl and left click and drag.

I seem to have vague memories of being able to swap this behaviour but it's probably a dream. Even if I could remember, I wouldn't do it because I'd find it confusing.

Regards

Wow that works, Something new for me again.

Now is there a way to turn it on or off? As in the file at work it is always turned off.

Is there a way to turn off AutoFill?

Probably, but I can't remember and I can't find it.

Not sure if the attached picture helps

Nope could not find out what this does.