It depends on the source of the drop down box values.
If the source is a table or query, you need to edit the record in the table.
If the source is a list, you need to open the form in design view, click on
the combobox, and edit the string in the row source.
BE careful, if your combobox is bound to a field, you may suddenly have data
disappear from view. The misspelled value has been stored in a field in a
table and is no longer available as a choice in the combobox, so the combobox
may not show the misspelled value.
John Spencer
Access MVP 2002-2005, 2007-2008
The Hilltop Institute
University of Maryland Baltimore County