Posted by The VM Sage on Jul 5, 2008
If you know you’ve got a 64-bit processor in your machine and yet you cannot start a Virtual Machine (VM) that’s configured for 64-bit operation in VMware Workstation, ESX, or Server, I can say two things:
1) You very likely are using a recent Intel CPU, such as the Core2 and Core2-based Xeon.
2) Your machine has the VT (virtualization technology) disabled in the BIOS.
For some reason, a great many personal computers and servers with Intel 64-bit capable CPUs ship from the manufacturer with the VT setting disabled. I’m not sure why the manufacturers do this, as there’s no downside to enabling it that I can think of.
Anyway, the VT setting is required by VMware to run 64-bit VMs.
To fix this, simply reboot your machine and at the text screen, you’ll see a message to press DEL or F2 or something like that to enter the BIOS setup. Once in the BIOS configuration utility, simply locate the setting for VT or V-T or Virtualization Technology or something alone those lines. Enable the setting and then save-and-exit the BIOS (usually F10).
Now you can run 64 bit VMs in VMware ESX, Workstation, or Server on your Intel hardware.