Trouble unpacking RAR files

None of the DS files will unpack correctly. I've tried 7-Zip, WinZip, and WinRAR. Sometimes, I get this message that says "CRC failed", and that the file is corrupt. I finally got Animal Crossing Wild World to unpack, but then NO$GBA 2.6 would not work. Instead, I just got this Windows Message that said it stopped working.Finally, when I tried to play Pokemon Platinum, it said that “The Save Data could not be accessed. Please turn the power off and reinsert the DS game card.” What should I do?

Sometimes downloads become corrupted, and that is why WinRAR fails to extract them.
Use a download manager like FlashGet www.flashget.com to help avoid corrupted downloads.Refer to the Common Issues thread about getting NO$GBA 2.6a and No$Zoomer to get Pokemon Platinum to work.
https://www.romulation.org/forum/index.php?topic=1462.0