Found "my" solution
I had the same problem.
I tried to flash the ROM's kernel (boot.img). Opened my command prompt and typed:
fastboot flash boot boot.img
And it couldn't detect the command. That's why, I think, you'll have to put in the file you want to flash together with your fastboot.exe & adb.exe etc.
So just put your files in ex "C:\Android" and it will flash.
I had the same problem.
I tried to flash the ROM's kernel (boot.img). Opened my command prompt and typed:
fastboot flash boot boot.img
And it couldn't detect the command. That's why, I think, you'll have to put in the file you want to flash together with your fastboot.exe & adb.exe etc.
So just put your files in ex "C:\Android" and it will flash.