I am working on making planets in outer space. I have planet textures but the problem is that my planets don't look spherical enough. Can anyone make a scripted spherize tool or a filter compatible with windows 7.
Have you tried to create your spheres in paintshop/photoshop software?
In Corel (and the earlier Jasc versions) Paintshop there is a tool for rendering "Balls and Bubbles" found under Effects > Artistic Effects. This tool enables you to apply textures and lighting to a sphere. This may work best for you without diving into the 3d realm. (Not sure if Adobe Photoshop has such a tool but it seems highly likely.)
I created these spherical images in Corel Paintshop:
Sculptris starts the 3d modeling process with a sphere.
There is a quick video tutorial at the page bottom under "Projection Painting" that shows you how to import .psd files for model painting. Maybe you can tweak this into something viable.
Projection Painting: http://pixologic.com/sculptris/features/
I used Sculptris for these spherical images:
Have you tried Unicorn3D?
There are other freeware 3d modeling tools like Daz and Blender you may be able to grab a spherical image from, not sure about importing textures.