BOOT ERROR Sony walkman b135 say boot error after that power

It might be serious check out with the service centre ........

YOU ARE KINDLY REQUESTED TO FORMAT IT. THANKYOU.

Hello
boot error

Had the same problem and fixed it, was a bit tricky.
first download the following two firmware update files:
http://www.sony.co.uk/support/en/product/NWD-B103/downloads/FRM_NWD_B10x
and
http://www.sony.co.uk/support/en/product/NWZ-B135/downloads/FRM_NWZ_B13x_f

disconnect the walkman from the computer
press the reset button
start the first firmware update (NWD-B100_V1_3.exe)
press the vol- button on the walkman and keep it pressed while you insert it into the usb port and still keep it pressed until the firmware update program recognizes the walkman
check the "format device" (or something with format) checkbox
klick "Start" wait until the program says "Finished"
Close the update program
then start the second firmware update program (NWZ-B130_V1_01.exe)
klick "Start" wailt until the program says "Finished"
Close the update program
now the walkman should be empty, formatted and working again.