Car Alarms: 2001 subaru legacy, alarmtek, subaru legacy

Question
I have a 2001 Subaru Legacy. Last evening, I needed to replace the battery. The Subaru has a manufacturer alarm with a remote however, the battery in the remote died- so we have not used it for some time. Now, after replacing the battery in the car- the alarm on the car reset itself. Again, the battery in the remote is dead. Today, I replaced the battery in the remote.
However, the problem is this- My wife tried to start the car while the alarm was going off (alarming)  she thought if she started the car with the key that the alarm would turn off. (she attempted this twice) Unfortunately, now the car has no power at all. I tried to jump start the car and it is not getting power. I know it must have something to do with the alarm sounding and her trying to start it. Is there a "reset" somewhere??  Please help.

Answer
Please be more descriptive if possible.

"GOING OFF?"

I need to determine whether it's a factory alarm
issue or, if it's an aftermarket system you are
dealing with.

Is it: Headlights flashing, car horn honking
and a worded SECURITY" light in the dash flashing?
(doubtfull since none of the notes show this
car as having a factory alarm system)=FACTORY

Or,

is it: flashing parking lights,
an LED in the dash area, and a siren
going off?= AFTER MARKET

Let me know more on this to better
advise you on a course of action
to take.

Best Regards,

Robert Martin
CEO/ALARMTEK
CARALARMMAN.com