Alarm problem

Okay. I was away for a couple months and had my Vanden Plas parked at my girlfriends house. Codes enforcement went to her house and asked if it was running, and if so, she needed to move it so it's not an eyesore. She did so, and the car does have some electrical problems. The passenger windows don't go up or down, the windshield wipers don't work, the A/C and heater weren't working. Also, there was something draining the battery so every time I parked it, I had to unhook the battery. When I got back, I tried hooking up the battery, and the alarm started blaring. I tried everything I could think of, but nothing helped. I'm wondering if there's a sequence of key turns or any other type of situation I can do to stop this problem. Thank you in advance. I'm trying to get this bad boy back on the road.