2006 Ford Explorer trouble starting.

I looked at info for your security system, it is starter motor disable. I didn't see 06 ford Taurus in my database, so I looked at 05.
Battery has a full charge and battery connections all good?
We can usually do some tests to see if starter motor will crank the engine, but, if the security is the problem, it still won't start.
You can check for applicable trouble codes? Try a different key?

have you disconnected the battery for more than 5 mins before the trouble started, if so you have to reset the idle value by disconnecting the negative battery cable, put a shop towel between the battery post and cable, run a jumper wire from the negative battery cable to the positive cable ,which is still connected, leave it on there for 5 mins, remove jumper wire, reconnect negative cable to battery, when you start it, turn the key to the on position, wait for some of the lights by the speedometer start to go off, then start it

See if you can jump start the car from another battery which is sound. If you can then the battery you have is rubbish and must be replaced.

May need this:

If the headlights work, I would check for voltage at the key switch and the major fuses.
If nothing works, I would start at the battery and work toward the fuse boxes. Could be a bad ground connection too.

Figure by everything else you mean the radio,lights,etc? Is the engine turning over? What happens when the key is fully engaged? If the engine does not turn over the first place to look would be your fuses. Ensure that none look to be burnt or blown.If so replace and try again.If fuses look good Next step would be to ensure starter connection is good and starter is turning over.If the starter is not turning over then I would focus on it.Hope this helps.

yea got get you more troubles
just check the alternator is charging well and no battery light on dashboard it indicate the bad alternator
monitor your battery if it got old and cannot hold the charge any more
you said when you used another one your car turned on

Depending on the mileage you might want to check the timing belt or chain

Problly bad connection to the battery check cables if so try to clean battery post.

starting circuitry includes key battery and starter..wiring to and from each