While attempting to install a 64bit OS in ESX Server you receive the following message
Host CPU is incompatible with the virtual machine’s requirements at CPUID level 0x80000001 register ‘edx’.
host bits: 0000:0000:0000:0000:0000:0000:0000:0000
Mismatch detected for these features:
*Longmode; required when virtual machine is configured for a 64-bit OS.
The Virtualization Technology (VT) Extensions have not been enabled in the server BIOS.
To install and configure 64bit operating systems in ESX Server requires that Virtualization Technology (VT) Extensions be enabled in the server BIOS settings.
Change the setting on BIOS for Virtualization.