Upgrading a Dell Vostro PC to Windows 10 after you get a NX error

If you ran into an error about the CPU not supporting NX on a Dell Vostro (230 in my case) when you tried to upgrade to Windows 10 (or Win8.1), you will need to make a change to the BIOS first.

Boot to BIOS by pressing F2, then choose Advanced and then CPU Information, and then set the Execute-Disable Bit Capability to DISABLED.

You should also uninstall any non-Microsoft anti-virus apps that you have installed before the upgrade.