Make sure your computer is up to date (run windows update). Unplug all your USB and SD adapters. Reboot after updating. Once you are back in windows run CCleaner. As soon as CCleaner doesn't have any files or registry problems to fix, plug your USB or mSD card adapter back in. Then see if it will work.
Sometimes drivers are bad, out of date, or the computer needs a good scrub down so it can properly recognize the mSD adapter.
Still not working? Okay read all of this first before doing anything:
Open up My Computer. Can you see the used/free space bar of your mSD? If so, it's not properly formatted.
Diskwriter does a special FAT10 format which breaks Windows from displaying size and then crams everything into .ZIP file.
Go back into Diskwriter. Open up your mSD in Diskwriter. Look at bottom, how many MB is free? Does it even work/load?
If the format is wrong you will want to pull all your files off and start over.
First backup (copy the files off if you can). If you can't, then use Diskwriter to make savedata (backup.sav) files of the individual games.
THEN YOU HAVE TO DELETE ALL PARTITIONS AND DO NOT FORMAT the mSD using EaseUS Partition Master. Don't forget to APPLY your changes in EPM. Ok? Next...
When it is totally blank (unformatted and unpartitioned), open up Diskwriter and click on FILE>FORMAT to format from within Diskwriter. Select the unformatted mSD to format. If Diskwriter won't let you select the mSD, close it and just right-click format the mSD from windows. Open up Diskwriter again and see if it lets you select the mSD. After FILE>FORMAT from within Diskwriter connect your template by CHANGE TEMPLATE, and start writing your games back on.
At this point, it should work.
Then you want to RESTORE SAVEDATA for each game (that hopefully you made a backup of) and select your backup.sav files that match to the game.
From then on, you need to open Diskwriter and look in bottom left of window to see how much space you have left. It will need a few MB of space to create savedata, so leaving 1GB open is a good idea. If you are filling the mSD up to where it can't hold any more games without erasing savedata, you will need to trim your .3DS ROMs.
I have all my ROMs pre-trimmed using the ROM-TOOL:
First make a folder for your ROMs and put the ROM-TOOL into the same folder. Might also want to make a shortcut to RUN in that folder.
It's a cmd tool, so you will need to open up RUN from windows (type "RUN" into search from start menu or use your shortcut), drag the ROM_TOOL.exe into the RUN window, make sure to delete the "quotation marks" at the beginning and end. Should look like this in RUN:
Code:
C:\Users\YOURUSERNAME\Desktop\ROMFOLDER\rom_tool.exe -t name_of_game.3ds
The "-t" is to TRIM the file. Don't forget that. Nor can you have spaces in the .3ds name. So try to use "underscores_like_this".
Run it. You'll notice that the .3DS file will now be smaller. Do this to all your .3DS ROMs. You can easily fit 31 games onto 32GB and have plenty of space left for Sky3DS savedata. But only 31 games.
Trimming .3ds ROMs strips the free space away which sometimes holds savedata. If there is a certain game (Like MH4U or Pokemon) which you want to be careful about, THEN DON'T TRIM IT. Or that savedata might not work.
Now that you have read this... see if your mSD is formatted properly and try the above instructions.
Still having problems? Turn off your antivirus and sandbox. Firewall is ok. Try again. Sometimes AV and Malware protection blocks Sky3DS programs and tools. Sometimes it even block downloading the .3DS files. So yeah... last ditch scenario.
*sigh*
back to figuring out HxD private header IDs...