hello everyone , i found a thread online about resetting your gearbox , is this a good thing to do ? what are the pros and cons of doing so and what is the correct way to do it ........

Do you mean resetting the adaptive transmission?

Am not sure if that's what it is called ; apparently it resets your gearbox response or something like that but am not very sure

OK - I believe you are talking about the resetting the adaptive transmission settings. Yes, I have done it and it makes a difference.

Thank you so much for your feedback ; can you tell me what steps to follow if you remember them?

Turn the key to on so that all the dash lights light up.
Roll up the windows, close your sunroof and turn off everything that will draw power.
Press the accelerator pedal all the way down and hold it there for at least 15 seconds.
With the pedal still pressed all the way down, turn the key off but leave it in the ignition.
After the key is turned to the off position, you can take your foot off the pedal.
Sit in the car quietly and wait for about 3-4 minutes. Do not open the door or turn anything on.
Remove the key, put the key back in the ignition.
Start the car and drive it.

If you want it to shift at higher points, you will need to drive it a bit more aggressively for the first couple of days. If you want it to shift at lower points, then accelerate slowly for the first couple of days.

I hope that helps.