If I design an .ADP project in 2007, will users be able to use this if they only have Office 2003?
...or is there a way of making an exe file with Access projects?

Someone else probably has a more complete answer for you however,

It is my experience that you can go UP in Access but you can rarely go DOWN based on the version.

That is, Access 07 can open an Access 03 database, but Access 03 probably won't be open an Access07 database

I think your best route is to develop an .mdb database.
Go into Access Options and select Access 2002-2003 as the default before creating the db. This will give you the right format.
You can always easily change the default back to Access 2007 once you have created your db.
If you use the Access 2007 format then Access 2003 will not be able to open it.
HTH

Hmm
Might have got that wrong - getting a bit muddled between .adp and .accb.
Must be old age and too many acronyms flying around - perhaps it is time for lunch!

Malcy

Given the status of the .adp (on its way to being depreciated), I wouldn't recomend new .adp projects at all. Use linked tables from an .mdb. If you are careful, you can create the .mdb and work on it with A2007 and it will still be usable by users running A2003.

If you are careful, you can create the .mdb and work on it with A2007 and it will still be usable by users running A2003.

That is interesting - I take it then that usability is not automatic. What sort of things should one take care with?
I thought that so long as the default format was not 2007 it would be OK in ACC2003 but your response suggests there is more to it.

You need to take to not use any features that are not available in earlier versions. Embedded macros and multi-valued fields come to mind but there are others.