2000 audi a8 4.2 Quattro need to program my keys for my audi. Not the fob
 

How do I program my keys I got two keys I'm not trying to program my key fob only the keys I used to know how to do it but I forgot now I'm trying to look for it online but I can't find it can you please help me thank you

You mean for the immobilizer? For that you need the security PIN from the cluster, search how to get the security PIN using a computer and cable, or pay someone in your area to get that PIN for you.

Example search result:
https://www.audiworld.com/forums/a8-...01-s8-2873134/

no what I mean is that when I put my key fob key in the ignition and turn it to turn it on it turns on but right away turns off and the dash shows the key flashing meaning it's not programmed what I want to do is program my key so when I turn on my car it stays on

That's the immobilizer, related to the little RF chip inside the keyfob.

If this problem came out of the blue it could be addressed by unplugging and replugging the cluster connections, I had that happen in my 2001 and unplugging the cluster for a short time fixed it.

If instead you have a new keyfob that has never been paired to the immobilizer you need the PIN as above and then you can pair keys with VCDS or similar software.

You don't program keys (or keyfobs). Your keyfob transponder chips are unique and do not change. The vehicle immobilizer module, located as a sub-component of the instrument cluster, LEARNS each unique keyfob transponder chip. So, technically, you are programming the immobilizer module.

The immobilizer transponder chip is located in the keyfob. The key still needs to be cut to fit, but without the fob recogized by the immobilizer, the engine might start for 3 seconds and then quit just like you described. You need the IMMO access code which you can't just get from a standard VAG-COM. Ross-Tech specifically states on their website that they will not enable that function on their product do to liability of people using it to steal vehicles. Breaking the physical ignition lock cylinder is easy, defeating the immobilizer is much more difficult without specific knowledge or equipment, therefore making it much more secure.

I don't know where you are located in the world, but there are certified NON-DEALER locksmiths who have access to equipment that will pull the IMMO code from the cluster. Without the IMMO code AND a VAG-COM, there isn't a way for the home mechanic to adapt new keyfobs to their car.

Scroll down on the home page - How to: Pull your Immo Code...

Just take off the positive wire off the battery post and let the car forget it's hard life for a night, that fixed my dad's bug with the same problem.