Your HP Pavilion dv2000 is likely experiencing a hardware issue. Four beeps on startup typically indicate a critical hardware failure—commonly a problem with the RAM or motherboard. First, try removing and reseating the RAM sticks or replacing them if possible. Also, check for any loose connections or debris in the RAM slots. If the screen remains black and beeping persists, the motherboard or GPU might be faulty—a common issue with older HP dv-series laptops. Try an external monitor to check if it’s just the screen. If nothing works, professional repair or replacement may be necessary.