The first option is to exclude a specific application, to do this, complete the following;
1. Click Start
2. Select Control Panel
3. Select System
4. Click the Advanced tab
5. In the Performance region select Settings
6. Click the Data Execute tab in the dialog box that opens
7. Select Turn on DEP for all programs and services except for those I select
8. Click Add.
9. The open dialog box will open. Browse and select your application.
10. Click Open
11. Click Apply
12. Click Ok
Alternatively, to turn DEP off, edit boot.ini and set the following switch