I need new computer... Well, when watching from the internet setting it says that the speed is 100mb/s... So, my computer just isn't able to take everything from it...
Is 100mbps written in your contract with your ISP?
If not, then you won't get it. Basically, Ethernet (the LAN technology that everybody uses now), has 4 speeds - 10mbps, 100mbps, 1gbps and 10gbps (the network cards for this are very expensive). What your computer is showing, is most likely the speed of the connection from your PC to your switch or router, or maybe the ISP, but it does not mean that you are going to get that.
It says 1gpbs on my connection, but I only get 200mbps as per contract. Before that, the connection to my DSL modem was 100mbps, but the internet connection still was 4mbps/768kbps. And the rest of the PCs saw 1gbps, because that is the speed of my LAN.