so i download the nvidea think to opne and edit .dds files , but how i can save it ? when i click to save there is a lot of info that i dont understand
If the image you want to save has an alpha channel (transparency), save with dxt5 compression. If it doesn't, use dxt1. And unless it's a texture for the HUD or similar, then generate mipmaps. I've not used the nvidia tools before, but you can probably leave everything else as the default.