At first I was getting some errors like these below:

Hyper-V launch failed; Either VMX not present or not enabled in BIOS.
Hyper-V launch failed; at least one of the processors in the system does not appear to provide a virtualization platform supported by Hyper-V.
This was happening because I had missed the Execute disable setting in the BIOS. To fix this, boot the computer and press F2 to enter the BIOS.

In the BIOS you need to change the following settings

Security > Execute Disable (set to On)
Performance > Virtualization (set to On)
Performance > VT for Direct I/O Access (set to On)
Performance > Trusted Execution (set to Off)
Save and exit the BIOS, then power the computer down. You must power it down for the settings to take affect.

You will now being able to run Hyper-V on your Dell workstation!