Battery Light ON on 2000 Volkswagen Jetta

I had not used my car for a week. Turned it on this morning and the battery light was on. Drove around for a little bit and went to auto zone. When they went to run the battery test, it said battery needs charge in order to retest. When I went to turn on the car, it would not start. Replaced the battery and the light is still on. The alternator is a year old as well as the battery that I removed.

Asked by for the 2000 Volkswagen Jetta
It sounds like your new alternator is not charging. Check the alternator belt first.
The fact that "battery" lamp is on means that portion of the charging system , the lamp circuit provides exciter voltage and has a path to ground through the alternator , is OK. The alternator output needs to be checked.
Incidentally if you recharge your old battery and check it again you may find it to be fine.