Primary key or index cannot be created on column '<0s>' because its data type is '<1s>'.

Microsoft Office Access 2003

Primary key or index cannot be created on column '<0s>' because its data type is '<1s>'.

You have included in an index or primary key a column whose data type precludes its participation in keys or indexes. Change the column’s data type or remove it from the index or primary key.

For the rules restricting the data types of index and key columns, refer to the Microsoft SQL Server documentation.