Drop-down lists in Excel are helpful if you want to be sure that users select an item from a list, instead of typing their own values.
1. On the second sheet, type the items you want to appear in the drop-down list.
2. On the first sheet, select cell B1.
3. On the Data tab, click Data Validation.
The ‘Data Validation’ dialog box appears.
4. In the Allow box, click List.
5. Click in the Source box and select the range A1:A3 on Sheet2.
6. Click OK.
Tip: If you don’t want users to access the items on Sheet2, you can hide Sheet2. To achieve this, right click on the sheet tab of Sheet2 and click on Hide.
7. You can also type the items directly into the text box, without using Sheet2. This gives the exact same result.