I don't own the software, and have not found the specs online, but I will be willing to bet since it can be configured with Dark Basic that you will need DirectX 9.0c added to your system.
This does not replace DirectX10, but will sit alongside of it. DarkBasic products do not use DirectX 10.
For more help check out this Vista/Windows 7 compatibility thread.
http://forum.thegamecreators.com/?m=forum_view&t=104612&b=1
I also apologize for taking so long getting back with you. I lost my internet connection before I could follow up, and see if you had replied.