Why does it put windows in images supposed to be underground.?

Firefly can't handle negative prompts. And it doesn't know that underground means "no windows", particularly when you then mention windows in your prompt

Hey @Joakim33678197ul0j 

Ya... that is a bit of a tricky prompt. 
I got some success using "cave".
cave rusty walls, old machinery, and pipes, side view
https://firefly.adobe.com/public/t2i?id=urn%3Aaaid%3Asc%3AEU%3A9941615e-586f-4799-a284-55bd64e98290&ff_channel=shared_link&ff_source=Text2Image

In situations like this @Joakim33678197ul0j remember to give a thumbs up or thumbs down; and, you can provide additional feedback about what you liked or didn't like about the image. Someone actually does read this feedback. They do appreciate such feedback as well.

If you have an image, you could use that as a style reference or composition reference. another helpful tip is look under Adobe Stock image. There are many free images that may or may not match your outcome. Look at the tags 
people are using to identify her/his image.  

After looking at the Adobe Stock Images, it is easy to understand the reason that FF is confused: the ceilings often are lite or look like they have windows. 

Remember the FF is trained on Adobe Stock images. Using a free asset could save you time and effort. 

If you have PS you can take those windows out as well. In PS, you can use Gen Fill and edit out those specific areas. 



Cheers,
O. Nate