The guest operating system that you specify affects the supported devices and available number of virtual CPUs.

When you create a virtual machine, you specify the guest operating system by using the setGuestOS(GuestOS guestOS) method of the VMTypes.CreateSpec class. The GuestOS class defines the valid guest OS types that you can choose from for configuring a virtual machine.

After the create operation finishes successfully, you can install the guest operating system on the mew virtual machine in the same way as you install it on a physical machine. For further information on installing a guest operating system, refer to the Guest Operating System Installation Guide at http://partnerweb.vmware.com/GOSIG/home.html and the vSphere Virtual Machine Administration guide.

Starting with vSphere 7.0, you can use the vSphere Automation APIs to install the VMware Tool on the quest operating system and perform some guest OS customizations. See Installing VMware Tools.