As of operating systems, both Linux and Solaris have already adopted this technology for years, but for the Windows operating systems this technology is only present from Windows XP SP2 on. So if you use Windows XP you need to have Service Pack 2 installed. You can check whether SP2 is installed or not by clicking on System icon on Control Panel (a shortcut to this is pressing Windows Pause/Break). If SP2 is installed, it should be listed under “System”. If it isn’t, you need to download and install it.

On Windows XP SP2 and Windows Vista, you can check whether NX technology is correctly enabled or not by clicking on System icon on Control Panel (a shortcut to this is pressing Windows Pause/Break). On the window that will show up, click on Advanced tab, see Figure 3.

click to enlarge
Figure 3: Advanced system configurations.

On this window, click on the first Settings button, the on “Performance” field. On the window that will show up click on Data Execution Prevention tab, see Figure 4. This is where the NX technology is configured.

click to enlarge
Figure 4: Configuring NX technology.

As you can see, there are two option: “Turn on DEP for essential Windows programs and services only” and “Turn on DEP for all programs and services except those I select”. The main problem is that the first option is the one selected by default. This means that this technology will protect only essential Windows programs and services. With this configuration NX technology won’t protect you from a virus or Trojan Horse if they attack a regular program, for example.

Thus we recommend you selecting the second option, where all programs and services will be protected by NX technology. If in the future you have any kind of false positive – i.e. Windows complaining that a program that you know that isn’t infected is trying to execute code on a memory location mapped as data area –, you can simply go to this window and add the program that is a false positive to the list of exceptions, by clicking on Add.

Click on Ok, restart your computer and now your PC is truly protected with NX technology. But like we said, with this technology you still have to use an anti-virus program and keep it updated. This is just an extra feature that adds an extra security layer to your PC.