By default VMware ESXi 5.0 (VMware vSphere Hypervisor) installs in 60 days Evaluations mode.
Licence key can be obtained for free from www.vmware.com. To update the license key perform following:
- Login to your host unsung VMware vSphare client
- Change to Configuration tab click on Licensed Features and click Edit
- Select Assign a new license key to this host and click on Enter Key
- Enter the key and click OK