Image source: http://www.miarec.com/files/MiaRec/Firewalls/BitDefender/BitDefender1.png
Firewall is computer application that continuously monitors your network traffic. Firewall alerts you and prevents any abnormal behavior on network access or access to unauthorized websites. In short, Firewall is security guard sitting at the get of your computer network and do not allow any kind of data to go outside or to come in without your permission.
Top most reason of Low Internet Speed.
Many internet users might have experienced that their internet speed is slowing down after few days or months of fresh installation. That is because during these times you may have installed many applications software to meet your needs. Other reason may be virus infection to your computer.
Too many applications may slow down your computer and internet speed because of following possibilities.
1. Many applications keep checking for updates on internet by visiting vendor's website.
2. Many applications like animated screensaver, your browser's toolbar, games may behave like spy ware and keep informing their vendors about your computer preferences and your browsing habits.
3. If your PC is infected by viruses, there are chances that they are accessing internet behind the wall and you feel that your Internet speed is slow.
For first two of the above solution, you only need properly configured firewall software installed in your PC, while for the third solution, you need to make your PC virus proof first by installing and upgrading latest antivirus software.
There are many free firewall applications are available for home users but choosing the best requires some effort. If you are purchasing full PC security software kit from antivirus vendors, you may get inbuilt firewall but when you want to install free firewall from different vendor, I will recommend searching for the best. You may try 'free Windows firewall software review' keyword phrase to search in Google for reviews.
Once you have installed the firewall, it will start asking you about each application that is trying to access internet to allow them or deny. You can allow or deny each of the applications for that instant or permanently by selecting 'Remember this setting for this application' option. This way firewall will learn to allow internet access to the application say internet browser and antivirus update program only allowed by you, and will start blocking other instances from accessing and eating your internet bandwidth.
If any of the webpage or web server application tries to attack your PC on different TCP port in suspicious way, firewall will also block it and inform you about. If any of your network computers tries to harm your PC, you will also get notification of it. Hence I say that firewall software is of same importance as antivirus software.
