Your users must have Access installed in order to use your application.

If you want to be able to accomodate users who don't already have Access,
you can purchase Visual Studio Tools for Office (VSTO) and distribute your
application along with a royalty-free runtime version of Access.

You need to purchase the following in order to create an Access 2003 runtime
application:

- Microsoft Access 2003
- Visual Studio Tools for Office 2003 (which includes the Access 2003
Developer Extensions)

The ADE is the product that gives you the license to deploy the 2003 runtime
components and you have to have Access 2003 installed in order to install
the ADE.

If you're using MSDN, note that while VSTO is available in all subscription
levels of MSDN, the Access Developer Extensions are not included with all
versions. ADE is only available at Universal level.

The stand-alone VSTO box includes both VSTO and the ADE.

See http://msdn.microsoft.com/vstudio/office/officetools.aspx for more
details