How do I play games on a DS emulator?

[Dr. Stinger A. Zoidberg]

I have already downloaded the emulator, How do I play the games, everytine I try to, it says "this is file nds" Help please?

 

[Slyfox696]

I have already downloaded the emulator, How do I play the games, everytine I try to, it says "this is file nds" Help please?

Where did you get the emulator from, and what emulator is it (if there are multiple options)?

 

[Lee]

lol DS must be the worst emulator as a lot of the games are touch screen

 

[Dr. Stinger A. Zoidberg]

Where did you get the emulator from, and what emulator is it (if there are multiple options)?

I got it from some website, its the NDeSmuME