I have tried everything I can find on Google... downloaded a file (xarc) that was supposed to help me, but its not working.
I have no idea what I do wrong.

I am at the station, and det worker is not giving me a number, that I am supposed to give to the lady.
He is just telling me that the paper I have, is old.

Please… I am not good at this computer-stuff (or English ;) ), but I love the game.
And would like to play on.

My last playthrough has been a while, and I remember there was a crash bug in the police station which is obviously not your problem. Googling around a little using parts of your description brought me to this page

which I quote here:

In the next scene you are inside the police station. Talk to the woman at the counter.
She refuses to let you in. Talk to her until you learn that the workmen are having lunch.

Talk to the fat workman. Talk to him until he mentions that a special form is needed to make them go to work.
Go to the Sliding Doors, and look at the Toolbox on the floor.
There is a piece of paper in there, pick it up it is an old form.

Try to give the form to the fat man, he will reject it and tell you the number of the needed form.
Go to the woman behind the counter and ask for that form.
Use this new form on the fat man, he will reject it again and tell there is an A missing .
Go to the woman behind the counter and ask for this form with an A.
Now you have got the correct form, and both men go to work on the doors."

I hope this helps you in your current problem?