I got a Gateway DX4200 Series with 5 GB RAM and a AMD Phenom 9150e 64-Bit Quad Core Processor from my cousin like 4 years ago. But Windows Firewall NEVER worked when I got it. It's not malware or a pressing issue as the computer doesn't have internet. But is there any way to fix it, it is just really annoying? I have tried to reinstall it with the Windows Defender download. But it says "Windows Vista SP2 comes with Windows Defender. You don't need to install this software.". As I said this is not a pressing matter so take your time.