many many thanks rolycat! I solved the problem! it's very very simple , but i 'm confusion!
With Ultra sigma and lan connection i envoyed SYSTem:OPTIon:UNINSTall and click send command
in the display oscilloscope appeared " Option unistall success! After i connect link to web for key generator and repeat again the procedure:
insert the serial number product oscilloscope, insert the code option DSER and receive the new serial number with the last two groups alphanumeric different from the previous one. I insert the key code with the manual mode with knobs of the front panel oscilloscope and ... BINGO the procedure it's succefully!!! Il the list of options "official" not appeared the function 500mV... it's correct?