Bon, je pense tout faire comme il faut pourtant mais ça marche po
"C:\Users\arnau.DESKTOP-92MLMSR>C:\Users\arnau.DESKTOP-92MLMSR\Desktop\DFUupgrade\DfuSeCommand.exe 0 C:\Users\arnau.DESKTOP-92MLMSR\Desktop\DFUupgrade\P2_D262.dfu
0 Device(s) found. Plug your DFU Device !
Target 00: Error Code: Unknown error 0x12340005.
Target: 00
Error Code: Unknown error 0x12340005.
TransferSize: 0
DFU State: STATE_IDLE
DFU Status: STATUS_OK
Request: (unknown 0x8C000000).
CurrentNBlock: 0x3976EC11
CurrentLength: 0x7680F1
Percent: 0"
Là, je suis "sec" ....
J'ai débranché, rebranché le casque.....