Select the 'Enable AutoComplete for Cell Values' check box in the 'Options' dialog box.
To turn AutoComplete on:
1) Select the 'Tools' menu and select 'Options...'. (The Options dialog box appears.)
2) Click the 'Edit' tab.
3) Check the 'Enable AutoComplete for Cell Values' check box.
the Enable AutoComplete for Cell Values check box 4) Click 'OK'.
the Enable AutoComplete for Cell Values check box