How to convert to template and create customization file using vCenter Server

 

 Before creating template you have to create virtual machine for template, which will be installed drivers, vmtools, disable or enable F/W, setting of IE etc if you want.
Select convert to template

In menu of VMs and Templates you can see your template.

If you want to create customization file for VM in advance, select Policies and Profiles > customization Specification Manager.

 Enter customization Spec Name

I recommend to select Use the virtual machine name............

  Select Generate New Security ID absolutely