Physical Address Extension (PAE), NX processor bit (NX), and Streaming SIMD Extensions 2 (SSE2) are the characteristics of a processor. PAE makes 32-bit processors capable of accessing physical memory greater than 4 GB on some supported Windows versions. The second feature ‘NX’ helps to secure your Windows computer against attacks by viruses and other malware. If your processor supports PAE, then only you may have NX feature on your PC. A majority of processors also include a standard instruction set called Streaming SIMD Extensions 2 (SSE2). SSE2 is primarily employed by third-party apps and drivers. SSE2 is critical to improving the reliability of these applications and drivers and to make them function properly. In order for you to upgrade to or install Windows 8, all of these features are a prerequisite. In case your processor does not support these features, then you can make a switch to Windows 8. The Upgrade process would fail with an error if your processor does not have built-in PAE and SSE2 features. In addition, you may receive a notice if the processor is not designed to support NX or you have NX turned off. In the latter case, the Windows Installer will attempt to enable this setting and, if it has no luck doing so, it will terminate with an error.
The NX setting can be turned on for the processor by configuring your PC’s BIOS, in case it supports NX. The method by which you can access your computer’s BIOS will entirely depend on your manufacturer. In general, you require pressing a key or a combination of keys during the Windows boot process to get to the BIOS screen. After you opened the BIOS, find the NX or XD settings on the Security tab. If there is no such setting, this implies your PC is not configured to support NX. In this case, there is no definitive method you can use to install Windows 8:
The following error message shows up when you upgrade to Windows 8 without having the PAE, NX, and SSE2 support:
‘Your PC’s CPU isn’t compatible with Windows 8’
Prior to starting the Windows 8 installation, you must check if the processor has PAE, NX, and SSE2 features. To do so, you can use the command-line tool ‘Coreinfo’ as follows:
- Navigate to ‘technet.microsoft.com’ to download the Coreinfo tool zip file. After extracting the zip, you will get an executable file.
- Go to ‘Start’, type ‘cmd’ in the search box and hit ENTER. This will open the command prompt.
- Specify the path to the executable that you got after unzipping the downloaded file at the command prompt. Press ENTER on the keyboard.
You should enter the full path to the exe file, for instance
- The command prompt will show you a list. You need to search for the PAE, NX, and SSE2 entries in this list. If you find a ‘*’ against a feature, then it is supported by your processor. You can check for this character next to PAE, NX, and SSE2 features.