How do I find out if I have DirectX 8.1?

Follow these steps:

1. Click Start and select Run.

2.Type dxdiag

3. Click OK or press Enter.

4. Look at the System Information frame. The last item should say DirectX Version.  If it says 8.1 or higher, then you already have it. If it says something else, then you need to download the newest version before you can use IsoEngine.