Excel Drop Down List
The simplest kind of Excel drop down list is created using the Excel data validation options. To do this:
Enter your possible options values into a column (eg. cells A1 to A10) - you can always hide this column later
if you don't want it visible.
Select the cell (or cells) that you want your drop-down list to appear in (cell C2 in the example on the right)
In Excel 2003: Select the Data Menu from the top of your
Excel spreadsheet and from within this menu, select the option Validation...
In Excel 2007 or Excel 2010: Select the Data Tab from the top of your Excel
spreadsheet and from within this menu, select the option Data Validation→Data Validation...
The Validation menu will appear. Within this menu :
In the first box, select the option 'List'. This should cause further options to appear.
Ensure the option 'In-cell dropdown' is ticked
In the 'Source' option box, enter the range of cells where you typed in your original list of options (eg. $A$1:$A$10).
If you prefer, you can enter this range using the mouse, by click on the symbol at the right of the 'range' box
and then select the range of cells with the mouse.
Your selected cell should now contain a drop-down menu containing your list of possible values.
To tidy up the spreadsheet, you might want to hide the column that contains the orignal list.
The resulting drop-down list is shown in the spreadsheet on the left.