Blackberry curve wont turn on but red light is flashing?

first take battery out and sim card and leave for 15mins, then replace and see if it re-boots, if not download the blackberry desktop to pc. www.blackberry.com/desktopsoftware. then connect your phone to pc with usb lead, when all connected, click on updates on the panel that will come up on your pc screen. before i forget it will backup your phone, install update then restore data to phone, be patient as this can all take around an hour.