CPU not compatible – Windows 8. Enabling the non-executable (NX/XD) flag.

So you have decided to try out a release preview of Windows 8! But on install it throws up an error stating –
“Your PC’s CPU isn’t compatible with Windows 8”
This usually means that the NX (Non-eXecutable) bit is not set.

Here is how you can go about fixing it.

Step I. Check if your CPU supports the Non-eXecutable flag.

Download and run coreinfo.exe

Running coreinfo will show you information on your PC’s cpu. Check here for an entry NX or XD flag. If present, your cpu does support NX flag. Yippie!!!.

Step II. Try enabling the NX/ XD flag using BIOS

  1. Restart your computer and go to the BIOS settings.
  2. Open the Security tab.
  3. Check for the NX or RX flag and enable it.

Step III. To enable the NX/ XD flag (using Windows settings – Win 7/ Vista)
If there is no option to enable the offending flag using your BIOS settings, you can try and from your existing Win 7 or Vista (provided that’s present on the computer you are trying to install Win 8 on). Here’s how –

Open up the ‘Performance Options’ window by

  1. Right Click ‘My Computer’
  2. Go to Properties, this brings up the Control Panel\System and Security\System window.
  3. Select ‘Advanced System Settings’, this brings up the ‘System Properties’ window
  4. Go  to the ‘Advanced’ tab. Click the ‘Settings’ button on the Performance panel, this brings up the ‘Performance Options’ window.
  5. Go to the ‘Data Execution Prevention’ tab.
  6. Select the option to ‘Turn on DEP for all programs’

Setting the NX bit in Win 7/ Vista

Restart your PC for the settings to take effect.





About 925coder

Father. Husband. Programmer. In that order. I love writing code, in all languages, all platforms. In my day job I am the lead architect in a software company creating products for the finance industry, mostly using Microsoft .NET technologies.

Posted on August 21, 2012, in Tech. Bookmark the permalink. Leave a comment.

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