FRDM-KL25Z bootloader

I have a problem when try to upgrade my board & now is blocked, it don’t even show in W10 & can not access to it to upgrade & and don’t found the firmware.s19 too.
I try to update to [20140530_k20dx128_kl25z_if_opensda] & this damage the board.
What i can do?
any help…
Thanks…
Excuse my English…