Can I return an open box but not open computer with no box?

Over the weekend I bought a refurbished mini pc to use as a streaming device to off load the stream processing from my gaming pc.
https://www.microcenter.com/product/675412/hp-elitedesk-800-g5-mini-desktop-computer-(refurbished)

The item came in a plain cardboard box, inside was the computer in shrink wrap, a boxed keyboard and mouse, and a power cord.
Because I had opened the box to look at the computer, my roommate thought on Trash Day (Monday) to just recycle the main box it came in… even though I didn't know if I wanted tor keep it

The computer itself is still shrink wrapped and accessories have never been opened.
Can I return it?

It's technically both opened and not opened.