It is becoming increasingly impossible for casual users to maintain their PC’s and workstations. While the most glaring culprit is Windows XP, virtually any modern operating system can provide a variety of configuration pitfalls.
At the top of the list is the current trend in firewalling, it seems a year ago only the Linux users were running firewalls and now nearly every product you install on your Windows workstation includes a firewall. This can make things especially daunting when you are looking to actually circumvent this protection. A great example is trying to open a bi-directional port through a firewalled cable modem router to your firewalled PC, in fact this invariably requires a connection to a firewalled server at the other end.
Not only do you have to get the port correct on the router, but you also have to reconfigure the services acting as firewalls on your Windows workstation to allow this protocol. While it is certainly beneficial that Microsoft has integrated a firewall with Windows XP SP2, they could have delivered this differently to customers.
Other vendors are even more guilty in this regard, simply installing an anti-virus package on your computer can introduce another firewall on your network interface. While all of this protection is beneficial, it comes at a price to the user.
For the most part, Linux has had this figured out for quite some time. The operating system kernel is responsible for the filtering, and a number of front-end solutions can be used to configure rules for the firewall. While the rules can be specified differently and even managed from different applications, the settings only affect iptables filtering rules. Microsoft is headed in this direction, and vendors for other modern operating systems should consider these examples.