Does the laptop boot into the old operating system successfully, or does it beep then as well?
The beeping is from the BIOS and indicates an error when the system cannot report it any other way (for example video has failed or is not running yet). Who manufactured your BIOS chip? search the web for "{bios manufacturer} or {computer manufacturer} bios beep codes" for possible explanations. I found one reference that continuous beeping with a Phoenix bios indicates keyboard failure... another for Award bios in HP systems indicate system failure, such as overheating... (perhaps a fan blew?)
Hope this helps