Unable to run/extract game(s)

I downloaded a ROM for Pokémon White 2 (http://www.emuparadise.mobi/Nintendo...64833-download) today with my Nvidia Shield K1 Tablet. Unfortunately, when I tried to open it using DraStic, it told me that it couldn't open it and that I needed to extract the .nds file. Since then I've tried to do so with both ZArchiver and AndroZip. For some reason, neither work and I can't work out how to get them to. I can't find my internal storage on either and am limited to my SD Card.
When I try with ZArchiver, it tells me that I'm out of memory. I understand that this is due to Google trying to phase out SD Cards (or something like that), but the fix for that is to move the whole thing to your internal storage and to extract it there, which is a problem.
AndroZip is somehow much more of a pain and I'd prefer it if ZArchiver was used.

Use 7zip on a PC running windows to extract the archive. Then move the rom to your SD card.

ZArchiver should work just fine with anything both on an internal and external sd card however Drastic may only run things from the internal - don't remember. Make sure you of course have the space free to extract and make sure the download is complete.

You can also try my upload if you want which has the patch already installed in the second link (ap patch or else you can't level up)

http://www.epforums.org/showthread.p...ean&highlight=

You don't need PC or any of that nonsense. Download the 7Zipper app. It will unzip damn near anything and let you move it from internal to external and vice versa. That's weird because the updated Drastic app has a built in unzipper for 7z files.

If this is like any other Android you can go to your main Apps menu (where you would go to uninstall or move them to the Home screen) and find App Info. Move as much as you can to the SD Card, and anything else you can Clear Data or Clear Cache, or deactivate to free up memory.

You can also go into settings > Storage > Select Primary Storage and change that to SD so anything else you download goes there by default. This will keep system memory free and let you find it with Zarchiver and Androzip. I find AdroZip to be much more useful than Zarchiver although I don't remember exactly what features Zarchiver lacked. Probably the multi selection button IIRC.

If you already tried all this, IDK what else to suggest. Never played with a shield.