Why won't my car start after new battery installed?

Why won't my car start after new battery installed? - 1

Added (1). I recently replaced my old battery in my 2002 Honda Civic. It was going bad. I put in a new battery and all my lights work and everything seems to be fine but when I try to start car, it doesn't do anything. Again everything works great (lights, radio, etc.) but won't even turn over. Before I installed the battery it would turn over but now nothing when I turn the key. Won't even click. ANy ideas?

Because the battery isn't hooked up.

This is likely one of those "sidepost mounts". If you don't get that bolt in there just right you wil not get a good connection. Or in your case, just good enough to run the lights. Take the cables back off, scrub the cable end & bolt with a wire brush, reinstall.