2007 nissan xterra will not start when i try to start it there is one click, it still wont start with a jump

Probably your charging system is not working. Auto parts store may help you determine problem.

CHECK FUSE AT BACK OF RADIO

It sounds like a bad connection to the battery or starter so check your wireing something is likely loose you can follow the large red wire to the starting motor and pull on it to see if the problem goes away if it dose you still have to remove it clean and retighten

When you try to start does the motor spin but wont start or is there no noise at all, if its no noise at all then i would start by checking the starter and if it spins but wont start then try holding gas pedal down and cranking the motor with a dead battery it may have lost memory and will need to run awhile to relearn idle at start up and other readings you may need to hold gas pedal to keep running for a few minutes,start with this first.

immobilisor has cut in by the sound of it which means dealer only

SEE IF SOME ONE CAN GIVE YOU A HOT SHOT YOUR BATTERY MAY BE WEAK AND THAT CLICKING NOISE IS THE SIGN OF NOT ENOUGH JUICE GETTING TO THE STARTER

Try connecting a jump pack to the battery or take battery off and completely re charge the battery if u still get clicking noises it could be starter motor

Hi, check the fuse box for a blown fuse in the radio slot. sometimes during jumps, this fuse will blow.

There are a couple of immediate possibilities that come to mind. First - you could have fried the ECU/ECM (not sure what it's referred to by the NizMO folks) when you tried to jump the battery.
Second - the ECM/ECU needs to be reset when a new battery is installed.

When you attempt to start it, do you get anything at all? Any clicking, whirring, buzzing?

starter possibly going bad