SAM7S256 Security Bit

Hi. I have read the .pdf document of James Lynch for the Atmel board, which may not be dead, but my computer still don’t recognise my P256. I do many times the steps with the ERASE Jumper, I think that the security bit is set but I don’t know another way to clear it except the ERASE Jumper, who isn’t working. Please give me some suggestions what I should do. Best Regards !