No internet access

Hi everyone, today, I changed internet compagny. When I had the other compagny, I had a trouble where I had the no access connection problem. Well, it was hard to find the solution, but a dad of my friend (which is a specialist in computers) helped me and figured out that I needed a static IP to fix my problem. He got me a static IP and my internet worked and I could navigate. Well now that I'm with a new compagny,I figured out that I had the same problem, maybe because I needed to set up an other static IP. Since I forgot how to do it ( last time I did it with my friend's dad was about 4 months ago) I searched up on Youtube some tutorials, I tried it out but it didn't work at all. Most of the videos that I watched proposed to use the default gateway to put in the TCP/IPv4 gateway section but in my PC, there's no default gateway given in the command(cmd). I don't know if this might be the reason why I can't set up a static IP, but im having issues with it. I'm using a wireless connection and I have win7. I would've asked my friend's dad but they aren't living near me anymore. Hope someone can help me! Thanks!