I disconnected the battery of my '96 Golf to access the windshield bottle. WHen I reconnected the battery, the anit-theft alarm went off and now won't shut off. How do I disable this alarm?

You could try disconnecting battery, leaving overnight and then inserting ignition key and switching on before reconnecting the battery.

It has sometimes worked for me but in reality it seems you probably have an alarm immobiliser fault you need specialist help with.

Sounds like the 'Anti-Theft' vehicle immobilizer system has been engaged. If you have handy access to your Vehicle Manual, check there first to vehicle specific hints and tricks.

Alarm systems are supposed to 're-arm' themselves after an incident triggering an alarm. This may take a few minutes during which time it ignores the key fob transmissions. If you can open the door but the engine won't start with the key or start button, try resetting the alarm with the key in on the "ON" or "ACC" position and using your fob button. If the alarm starts again, silence it with the fob button again.
OR
(Assuming your battery is in good condition and the gear selector is in PARK or NEUTRAL) If you have access to the hood release, disconnect the NEGATIVE battery terminal for 10 minutes to force a reset of all electrical functions upon reconnection. Make sure you don't touch the cable to any other part by slipping an old sock or mitt over it for safekeeping. (You might lose your radio and climate control presets but they can be reset easily once the main problem is bypassed.) Test the DOOR LOCK/UNLOCK button to verify that power has been temporarily disabled to the entire vehicle. After the wait, reconnect the power cable securely and try to start the vehicle.

O.K. Jeanne lets start here did you disconnect the battery or did it go dead yes/no if yes when cables were reconnected ///or battery jumped the alarm went off putting the car into theft mode and that's why the no start condition flashing red alarm light=== you have to disconnect the battery again and when you reconnect it the alarm will sound when it does you have to press the remote control button///key fob to stop the alarm and you will be able to start the car please post back if there's something else and please the most important thing to remember is that any one here who wants to help you is not standing there with you so everything must be told be very specific about what's happened ///happening O.K.

Your problem is your BCM or known as body control module is looping into theft mode and in return not getting power to the starter so I'd check with ford on a BCM flash to factory default settings hope this helps you

i would disconnect the ground battery cable for about 1 minute and then reconnect it, then try and start the car, hopefully the light will have went out. and hopefully car starts.

1st of all Read Your owners Manual, Depending on the Radio you have in it will depend on the Alarm system . Also Completely Disconnecting the Battery Will Reset your Security System

After reconnecting the battery press the FOB 5 times that should reset the alar.

Sounds like you have a key without the chip in it. Replacement keys without the chip will only unlock the doors and will activate the theft alarm when you start the vehicle.

Put the key in the driver door lock (or the trunk lock if you don't trust the driver's door- quite often on a vehicle of this age the wires break in the door and it won't electrically de-activate the alarm due to the broken wires)
Disconnect the battery.
Turn the key to the unlock position (toward the front of the car if using the driver or passenger doors) and release it- it will go back to centered, but will retain slack in the forward direction
Then reconnect the battery. You may get one beep out of the alarm horn. If it beeps continually, turn the key to unlock again.
As long as the alarm is de-activated it will not prevent the car from starting. If you are still having a problem it is not alarm related.

Good luck and keep me posted, be glad to help