That's because you set Windows to open 7z files, which doesn't make any sense.
Just go to the proprieties of the file and change the type of the program that should open it to 7-Zip as it should be.
Desktop: Ryzen 7 5800X, Radeon RX 6800 XT, 2x8G DDR4 3600MHz, Manjaro Linux
Laptop: Ryzen 9 5900HX, Radeon RX 6700M, 2x8G DDR4 3200MHz, Manjaro Linux
Old Desktop: AMD FX-8350, Radeon R9 280X, 2x4G DDR3 1600MHz, Manjaro Linux