I am here to teach people how to use programs (mainly emulators) on their computers. Today I will show you how to use an NDS emulator named DeSmuME. Don't ask why it is named that, I don't know. Google it if you're interested! Let's begin.
Step 1: Download the Program
Welp, you can't get far if you don't download it.
Go to the official download page and download the version that your computer requires (eg if you have a 64-bit computer, go for the x64 version - if you have a 32-bit computer, go for the x86 version)
Unless you know what you're doing (but if so, why are you reading this tutorial?) do NOT download a Nightly build. They are full of bugs!
After you have downloaded it, extract the files somewhere.
Step 2: Open It
Now you have it downloaded, open it. You will see a window like the one in the picture. That is because we are not done. Proceed to the next step to find out what to do.
Step 3: Download Games
If you already have nds roms, you can skip this step and just go back to DeSmuME.
You forgot to download games! Here is a link to the Emuparadise page where you can download almost any NDS game! Click here. I do not support illegal gameplay, as in only download games you own!
They will be downloaded as ZIP or RAR files. You will need to extract them. After that, go back to DeSmuME.
Step 4: Run Your Games
Now, go back into DeSmuME and press File > Open ROM or Ctrl+O/⌘+O. Find where you extracted the NDS game and open it. Shortly after, the game should open. To see and tweak the controls, go to Config > Control Config.