My friend has a 1997 Land Rover Discovery.

When she went to go start it, the alarm started to go off. she took out the fuse for the alarm because it wouldn't turn off. afterwards it wouldn't start, the battery and oil light remain on. The battery was checked and is working correctly.

Is there anything that could be causing this problem?

 

Try putting the fuse back in and put the key in the drivers door and hold it in the unlock position to disable the alarm. Then try starting. My acura RSX did this to me down at the beach one time. The horn started going off and I got in the car to try and start it to turn it off but couldn't. I sat there for 20 mins looking at fuses and stuff before someone walked over and told me to try shuting the door and holding the key in the unlock position. It worked!!! I hope it's something that small for you too.

 

Sounds like you are immobilized, if starter does not turn the engine over, the alarm blocks the starter relay. Battery and oil light are on because alternator is not turning and charging battery, and oil pressure has not built up to above 7 PSI to turn off oil light. Perfectly normal, no panic yet.

 

Whenever the alarm is goes off you MUST close all doors, lock and then unlock the doors and the alarm will go off.
By removing the alarm fuse you just make things worse because the alarm then thinks you are trying to steal it instead of it just being a accidental setting off of the alarm.

This holds true for all cars with a factory alarm.

 

How was the battery tested and what was the voltage under load?

 

The alarm was the problem for the car not starting up. The alarm messed up from the computer or some wires being kicked on the passenger side of the car. some bulbs and wires needed to be replaced, after that was fixed then the car started right up with no problems.