Either in explorer go to Tools -> Folder options -> File Types, scroll to .nds file and then go to advanced -> Change icon, then select an icon to use for the .nds extention

or

Install the Cyclo Team's Evolution Tools and your .nds files will all have their proper icon in explorer. Like so -

 

guys... dont take this really peronally but.... I LOVE YOU GUYS XD thanks guys

 

it doesnt work bluestar:S maybey because i have an r4

 

someone?

 

i cant delete it WTF:S

 

open a normal window

tools->folder options->file types->search for nds click delete

 

OK, somewhere on your desk there should be something that looks like a TV. If you're reading this it'll be right in front of you. Move your hand to your right (if you're left handed you will have to reverse these instructions) and grab the plastic thing with the two buttons. Now, keeping an eye on the thing that looks like a TV, move the little pointer you see on it to something that looks like an actual cardboard folder on the screen. Any one of these will do. Press the button on the plastic thing twice. A square will pop up. DO NOT PANIC. This is normal. At the top of this square, click on the word tools. Now the words Folder Options. Now the words File Types. Now find the one that says NDS file (the files are in alphabetical order). OK? Click on the words NDS file. It will go dark blue. Click delete. And relax.

 

lol ty dudeXD i knew where the file option thing was but im not that good at english so i thought like wtf normal window..... but now it works...!!!!!!thanks everyone that help'd me!!!!! you guys are greatXD