u-boot flashing in mini6410

I've bought an mini6410 board with preinstalled WinCE.
Unfortunately, there is no u-boot.
How can I flash u-boot into NAND?

You need a computer with windows installed for this way:

- Use the SD-FLASHER(windows) and burn a uboot for SD.bin on it
- Switch to SD Card boot and start the mini6410 from the flashed sd
- format nand in uboot, upload uboot for nand.bin with DNW (windows)
  or dnw2 / xdn(linux)

When I try to burn u-boot onto SD card, choosing u-boot.bin file,
SD-flasher says: "Error: unrecognizable file".

I've also tried the same procedure with superboot. SD-flasher says that 
all things are ok. But, when I try to boot mini6410 from sd card, nothing
happens.

Did you started the SD Flasher as Admin (if you are using WinVista / 7)?

Thanks for advices.
The problem was just in SD card.
When I tried another one, all became work.
I don't understand is that a bug in bootloader or in hardware.