How can I disable my alarm on a 2001 Infiniti g20

For the past couple weeks my alarm goes off for no reason. Now my car wont start, or even turnover. I disconnected the battery and reconnected it. Then I tried to jump it. All this was to no avail. I figured that the alarm system may have disabled my car. Everything works, windows, air, radio, lights, just wont even turn over. Pleas help!