For The ones Who cant Oppen Progam

use in compability mode that works for me
I am using Windows XP (Services Pack 3)

Install DirectX 9 to 11
Install VC Visual C++ Redistributable Runtimes
I suggest Visual C++ Redistributable Runtimes All-in-One

After you do these things you are good to go also you can find older version on Internet Archive

I tried the latest version on Windows 10 today and its working. The tree models this program makes look fantastic. Exporting them into Blender and works if you do a few things.

Export as obj. Scale it down (you can probably do this inside the TreeIt editor beforehand). If you export for instance the Oak tree example and try to import into Blender as is, the near / far clip planes will be off and you won't even be able to see it and the tree will be over a 100m tall.

One you scale it down you have into the shader editor and connect up the Alpha node on the leaves material so the background of the leaves shows transparent. Then I noticed after exporting to .gltf format I could see the individual triangles on the mesh, so in Blender I set it to shade smooth and re-exported and now it looks pretty great. T

There might be a few more tweaks I can make but what I'm seeing is still way better than what you can find for free out there right now. Looking forward to really learning how to use this.

the steam version runs pretty good... and yes the program is nice, also the author sometimes pay attention to suggestions or ideas, he implemented an idea i was asking some time ago and it was pretty useful

This works thank you so much.
I feel like this program is having a bit of an [insert large and old software here (adobecoughcough)] moment, a super old base with extra features being bolted on.

Additional steps that might need to be taken are: (I needed to do this)
- disable antivirus temporarily before using the program
- click the blue box that appears. I am not sure why you need to do that but you must click in the blue box.