The emphasize of this study is to evaluate security issues for home users having a personal computer connected to the Internet. It focus on the usage of advantages and disadvantages when using a firewall while connected to the Internet. The hypothesis is that it gives a better protection to install and use a firewall compared not to do so, due to security flaws in the operating system. The prediction was tested on a home user's personal computer. The testwork was divided into two major tests, each of them performed with, respectively without, a firewall. These major tests were divided into five smaller semi tests. The first semitest without a firewall suffered from a virus or worm attack resulting in loss of data and log files. Durin...