It wont even boot

Hello,
Im trying to figure out what is wrong with my friends computer. she had about 630 viruses and I down loaded spybot and norton anti virus. About 3 days later her computer wont even boot it goes to the windows boot screan and when you let it try to boot it bleeps out and goes right back to the screan before. Is there anything she can do to get it working again the laptop is about 3 years old.