I got a Acer laptop and I want to connect the internet but I don't know where to put the access code from my DSL modem.

You normally get asked for the code at some point while configuring your internet connection if You need it at all.

Are you connecting this laptop via wireless?
Is your DSL modem already setup?

If your modem is not setup yet and you do in fact have DSL, you will need to call your ISP to set it up. THey will go through the process of providing you with the information you need to successfully setup and activate your DSL Modem.

Rick