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Ensuring Virtualization Technology is enabled on your VMware host (1003944)

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  • You are unable to power on a 64-bit virtual machine.
  • You see this error when trying to power on a 64-bit virtual machine:

    cannot find a valid peer process to connect to

  • The CPU is Virtual Technology-capable, but Virtualization Technology (VT) is not enabled.
  • You are unable to install a 64-bit operating system.
  • The virtual machine has been migrated and it no longer powers on.
  • You see one of these errors when trying to use vMotion to migrate a host that does not have VT enabled:

    • The CPU of the host is incompatible with the CPU feature requirements of virtual machine.
    • The CPU of the host is incompatible with the CPU feature requirements of the virtual machine; problem detected at CPUID level 0x80000001 register 'edx'.


Intel CPUs require EM64T and VT support in the chip and in the BIOS to run 64-bit virtual machines. This article helps you ensure your processor is VT-capable, and it also instructs you on how to enable this feature.


Ensure that your processor supports EM64T and VT.

All Intel Xeon processors feature:
  • Intel Virtualization Technology
  • Intel Extended Memory 64 Technology
  • Execute Disable Bit
Microsoft offers the Hardware-Assisted Virtualization Detection Tool. For more information, see the Microsoft Download Center.

You can check your processor's compatibility on the Intel Website.

Note: Intel Virtualization Technology (Intel VT), Intel Trusted Execution Technology (Intel TXT), and Intel 64 architecture require a computer system with a processor, chipset, BIOS, enabling software and/or operating system, device drivers, and applications designed for these features. Performance varies depending on your configuration. Contact your vendor for more information.

Note: Intel EM64T requires a computer system with a processor, chipset, BIOS, operating system, device drivers, and applications enabled for Intel EM64T. The processor does not operate (including 32-bit operation) without an Intel EM64T-enabled BIOS. Performance varies depending on your hardware and software configurations. Intel EM64T-enabled operating systems, BIOS, device drivers, and applications may not be available. For more information, including details on which processors support Intel EM64T, see the Intel 64 Architecture page or consult your system vendor for more information.

After you have confirmed that your processor supports VT, you may need to enable the support:
  1. VT must be enabled in the host system BIOS. The feature may be named VT, Vanderpool Technology, Virtualization Technology, VMX, or Virtual Machine Extensions. Often, you find this setting under a Security screen in the BIOS. The location of this setting varies depending on the system vendor.

  2. The VT setting is locked (either on or off) at power on. After enabling VT in your system BIOS, you can first save your changes to the BIOS settings and then turn off power to the system. When you turn the system on again, your changes take effect. If you simply reboot the system without turning it off, VT is not enabled.

  3. After you have power-cycled the system, confirm that your system is capable of running 64-bit guests by following one of these methods:

    • Boot from a CD containing the CPU Compatibility Tool. This is included on the ESX Server 3.x CD-ROM in /images/cpuid.iso or can be downloaded from the VMware Shared Utilities page.

    • For ESXi/ESX hosts, see Determining if Intel Virtualization Technology or AMD Virtualization is enabled in the BIOS without rebooting (1011712).
    • Some system vendors ship VT-capable systems without the ability to enable VT in the system BIOS. If you cannot find a way to enable VT in the system BIOS, contact your system vendor. An updated BIOS may be available.
    • Some laptops require a total power discharge to enable VT extensions once you have set it in the BIOS. To do this, disconnect the external power, and remove the battery from the laptop. Then press the power button on the device to drain all power. Once this is done, replace the battery and reconnect the external power, and verify you are able to utilize the extensions.
Note: The preceding links were correct as of February 11, 2013. If you find a link is broken, provide feedback and a VMware employee will update the link.

Additional Information

Example output from the ESX CPU Compatibility Tool:
Reporting CPUID for 2 logical CPUs...

All CPUs are identical
Family: 0f Model: 04 Stepping: 1
0x0000641d 0xbfebfbff 0000000000 0x20100000

Vendor : Intel
Processor Cores : 1
Brand String : " Intel(R) Xeon(TM) CPU 2.80GHz"
SSE Support : SSE1, SSE2, SSE3
Supports NX / XD : Yes
Supports CMPXCHG16B : Yes
Hyperthreading : Yes
Supports 64-bit Longmode : Yes
Supports 64-bit VMware : No

  • On Intel systems, the last line indicates Yes when the CPU supports EM64T and Intel Virtualization Technology (VT).
  • On AMD systems, the last line indicates Yes on any 64-bit enabled Opteron (Rev E or later).

For translated versions of this article, see:


64bit-os-installation-fails boot-guest-os boot-vm em64t-and-vt-not-enabled install-64bit-os intel-cpu intel-vt vmotion-vm

See Also

This Article Replaces

3282933, 10128, 10147, 1000462, 1000217, 2087

Update History

03/11/2011 - Updated all Intel links, added a Microsoft link, and added a link for ESX hosts. 01/11/2012 - Added additional error message in Symptoms

Request a Product Feature

To request a new product feature or to provide feedback on a VMware product, please visit the Request a Product Feature page.


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