Extraction Error with 7-Zip

[Dexter Willett]

I feel like I'm doing something wrong when extracting ISO and GCM files
Let's take Pokemon XD for example. I downloaded it from emuparadise, opened up the .zip file, and I have a list of split archive files, with one .rar at the bottom.

I know that the .rar itself contains the GCM file that lets me play the game, but extracting that only yields error messages.

I have the most recent version of 7-zip installed as of writing this post, and this has occurred with non-GCN games when extracting the .rar inside the bigger download. What can be done about this?

[Zaladane]

Start with the .r00 it will automatically combine the whole thing

[Dexter Willett]

Start with the .r00 it will automatically combine the whole thing

I'm still getting an error when I'm extracting the file after it combines