The promised free Windows 10 upgrade can become a real disappointment

So Microsoft got you really exited about the free Windows 10 upgrade. Unfortunately not all systems are able to run the new Windows 10 OS, even if the Windows 10 upgrade is presented.
Here’s what Microsoft says you need to run Windows 10 :

  • Processor: 1 GHz or faster
  • RAM: 1 GB for 32-bit or 2 GB for 64-bit
  • Free hard disk space: 16 GB for 32-bit or 20 GB for 64-bit
  • Graphics card: Microsoft DirectX 9 graphics device with WDDM driver
  • A Microsoft account and Internet access

So in order to be able to run Windows 10 (or Windows 8/8.1), you need a processor that supports PAE, NX, and SSE2. Without this, your Windows 10 fun comes to an end.

Now if you’re the sort of person who is a walking encyclopedia of tech trivia, then you might notice how these specs are the same as those for Windows 7. But there is one gotcha that you need to be aware of, and this only becomes apparent if you pull up the specs for Windows 8/8.1 and look closer at the processor specs:

  • Processor: 1 gigahertz (GHz) or faster with support for PAE, NX, and SSE2

Microsoft offers a handy primer on what these mean.

  • PAE gives 32-bit processors the ability to use more than 4 GB of physical memory on capable versions of Windows, and is a prerequisite for NX.
  • NX helps your processor guard the PC from attacks by malicious software.
  • SSE2 is a standard instruction set on processors that is increasingly used by third-party apps and drivers.

So, how can you tell if your processor supports all of this? There are a few ways:

  • Download and run the Windows 8/8.1 Upgrade Assistant. If your hardware is not up to spec, it’ll tell you, saving you gigabytes of downloads.
  • Try installing Windows 8/8.1. If it won’t work, the installer will tell you before you wade out beyond your depth.
  • Start the Windows 10 upgrade. The Assistant will check your system and tell you if the system will run Windows 10.
  • Download and run a handy utility called CPU-Z (portable version). Look under Instructions and if you see SSE2, EM64T (indicates the processor has support for PAE) and either VT-d or VT-x (which is what’s needed for NX support) then you’re ready to rock.
  • Manually check out your CPU by wading through this list. This will tell you directly if the CPU supports NX, and it will be listed as "NX / XD / Execute disable bit".

NX can be a pain in the behind because while your processor might support it, it could be disabled in the system BIOS, which then means having to dig around looking for the on switch.

To install a 64-bit version of Windows 8.1 (not Windows 8) on a 64-bit PC, your processor also needs to support CMPXCHG16b(which also, annoyingly, needs motherboard support, so it can be hard to test for), PrefetchW, and LAHF/SAHF, which adds more confusion. Fortunately, most people will have this already.

If you’re running Windows 8/8.1 then you’re probably good to go. If you’re not then the installer will tell you. Beyond that, the older your PC is, the more likely you are to be outta luck.

Se be prepared and don’t be disappointed when your upgrade to Windows 10 fails !

Greetz, M.