My dad tried taking my car out and messed something up.

From what he told me, he manually unlocked the car with the key, the alarm went off when he opened the door, he tried shutting off the alarm by pressing every button and finally started the car until it shut off.

Since then, the remote disables the alarm, but it does not unlock the doors. I now have to disable the alarm with the remote and then unlock the door manually.

Can someone please help me?

 

Sounds like he got the programming messed up with the remote fob, somehow. The easiest thing to do would be to take the negative terminal off the battery for an hour, then reconnect it. That should put the car back to the defaults.

Make sure that you have your stereo code written down before you do this, as you will have to enter that code into the stereo before it will unlock. If you don't know what I'm talking about, look at your owner's manual.

After doing this, the key fob will initially not work to unlock the doors remotely until after you've used it to drive the car. Once you've inserted it into the ignition and drove the car for awhile, it should be back in sync with the car, and it should unlock all doors.

The only thing left to do after that is to reprogram the "one-touch" feature on the windows. To to that, press and hold down the window button until the window is rolled down. Then, press and hold the window button up until 2 seconds after the window is fully up. Doing that for each window should reestablish that function.

There is a way to reprogram the fob without unplugging the battery, but it involves inserting the key into the driver's door lock, pressing the fob button until the side mark light flashes, and then turning the key. It's a little finicky to do it this way, however, so I think it's easier to just unplug the battery terminal for an hour.

Try googling "A4 B6 key reprogram", you may find a very detailed way of doing it without unplugging the battery.