dont you know anyone with a proper null modem cable and a pc with a com port will only take around 8 mins to flash.
if the 500 boots up you could always try flashwizard pro and flash it over lan,but if it hangs on flashing the only way for recovery is with a null cable and dream up.
if your going to try flashwizard make sure the dreambox and the laptop is connected directly to the router,this way you have more chance of it not hanging on flash.