You have the option of enabling or disabling activations in Virtual Machines: https://wyday.com/limelm/help/vm-hypervisor-licensing/
If what you're saying is that the customer is claiming they're not inside a VM, then see our FAQ: https://wyday.com/limelm/help/faq/#in-vm
If you've followed that FAQ, you're using the latest version of TurboActivate, and you still believe TurboActivate is not correctly detecting the machine as a VM or not as a VM, then you need to provide useful information: