When you type letters A and B in the Excel and drag down, instead of getting the alphabetical list A to Z, you get the repeated A and B.
There are different ways you can get A to Z list. The first method is to create a number list and apply the CHAR function.
Step 1: Create a list of numbers from 97 to 122 for lower case list a to z, or a number list from 65 to 90 for upper cases. Each number from 0 to 255 represents a character, please see the list;
Step 2: Use the CHAR function "=CHAR()" to convert the numbers to letters. For example, = CHAR (97) will return the letter "a".
The trouble to use this method is that you need to remember the numbers and the function. You can use the following method to customize the A to Z list, and you will get the A to Z list automatically next time.
Step 1: Click the "File" tab from the ribbon;
Step 2: Select "Options" from the menu on the left;
Step 3: In the "Excel Options" window, click "Advanced";
Step 4: Drag the scroll bar on the right down to the bottom and click the "Edit Custom List" button;
Step 5: Type the letter list A to Z or import an existing list from your file, and click the "Add" button to add the list;
Step 6: Click "OK" to close the window.