Is there any way i can change RAR files for my DS?

I downloaded a game for my DS and it downloaded as a RAR file. All the other games i got are NDS files and my R4 couldn't find it when i copied it over. And it seems all file types on here are RAR files

use winrar to extrct the .nds file from the rar http://www.rarlab.com/download.htm

You need to install winrar to extract the .nds file from the RAR arciveWinRAR Crystal Full version, DL hearhttp://www.mediafire.com/download.php?yewzygazglr

Just in case you don't know how to use WinRAR.BAMhttps://www.romulation.org/forum/index.php?topic=3880.0

Thanks very much for your help. Managed to sort it now. :) :)