You may need to enable the virtualization support in bios, and it may not be obvious where this is needed. I don't have an 8500 close at hand to look at.

Here is a post with the steps to check/change. 

http://en.community.dell.com/support-forums/desktop/f/3514/t/19468989

What software are you trying to run?

Thanks for the prompt reply.  Virtualization is enabled in BIOS.  I have tried using HAXM for Android and Genymotion for Android with Oracle Virtual Box.  All fail with the reason that VT is not available.

Win7 or Win 8.1? 

if Win 81, perhaps this will help.

http://windows.microsoft.com/en-us/windows-8/hyper-v-run-virtual-machines

For win7, I have an HP workstation with the same processor that the xps 8500 has ( i7 3770) running Win7-64 enterprise and I recall I had to change several things to get VMs to work. Sorry but I don't remember the details as this was a couple of years ago. I use oracle's virtual box without any issues.

Good luck... 

Thanks!  I am running Windows 10.   I suspect that the motherboard does support virtualization because the option is in the BIOS.  According to Intel, the H77 chipset also supports virtualization.  My computer is out of warranty so I may have to pay dell to fins out if the motherboard supports virtualization.  I also posted this issue on the Intel community forum.  Perhaps someone there can shed some light.

My computer is out of warranty so I may have to pay dell to fins out if the motherboard supports virtualization.

I'm 99% sure  8500s with the i7 3770 support virtualization.  

I haven't had success upgrading to Win10 on anything I care about so my win10 installs are limited to a 4 y/o core i5 laptop and a bunch of virtual machines running Win10 as guests of Win7 or OSX.

open powershell as an admin and type this command.

 systeminfo.exe

At the botton, my win81 system reports this: 

Hyper-V Requirements: VM Monitor Mode Extensions: Yes
Virtualization Enabled In Firmware: Yes
Second Level Address Translation: Yes
Data Execution Prevention Available: Yes

When I first attempted to activate virtualization, I followed the documented procedure and  enabled the HyperV function of Windows 10.  systeminfo reports "A hypervisor has been detected. Features required for Hyper-V will not be displayed.  I  tried disabling HyperV. This pretty much hosed my system.  I did a system restore and my computer is working again with HyperV enabled.  

My best guess is that you are correct,  It appears that I am stuck with an out-of-warranty computer with a defective CPU.  I had not attempted to run virtualization until now.

Which version of Win10 are you running? If Home, it will not run Hyper-V

www.microsoft.com/.../Compare

Hyper-V needs Pro, Enterprise or Education. I'm not sure if MSoft locks down some portion of the OS to prevent VMs from running but if so, it might also harm VirtualBox and other VM systems.

If it were my system, I would reinstall the OS that came with the system, and install Oracle VirtualBox and see if it worked before I blamed the MoBo or CPU. This feels like a software issue not a hardware one. I could be wrong but its cheap and easy to try by reinstalling Win7 or 81. 

Thanks for your help!

I am running Windows 10 Pro.

Would a software error cause the Intel Processor Identification Utility to report No Virtualization Technology?