There isn't any "free" interior design software. That is extensive by scanning a picture of a room into the software so you can change colors and re-arrange furniture and change furniture, etc. No freebies there.
Graphic art design? Well, Photoshop and all those offer a free trial "basis" download but is limited and time limited then you have to puchase it and register it to use it. [ AskJR's advice column | Ask AskJR A Question ]
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