I'm not sure if I understand what you're saying.
If you're seeing crazy characters in your SD card while just looking at it in Windows, then there's some corruption going on. A format *might* fix it, but the card might just as likely be dying.
Heres the steps for take: First, you put the SD card in your PC. You open it and put the bin update file right there. Not in any folder. Take the SD card out of your computer and put it in the Omega. Then put it in the GBA, and hold down R while you turn it on. It should go to the update/flash screen and not to the file selection screen.
At what point are you seeing Chinese characters?
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