I have an old Olivetti M300 pc. Recently battery died and I have replaced it. When I started it back up on Built in Settings, I must have put wrong HDU setting and now it keeps stating replace disc /disc error. I now know the HDU setting, but how can I get back to the page with the request for built in settings. I have tried disconnecting the battery but after 30 mins, I still get the same disc error lines on the screen. Is there a simple way to do it. :(