Oracle VM can support multiple guest O/S including Windows server. However the configuration on the Exalogic, due to the SR-IOV Infiniband drivers, paravirtualised (PVM) mode, Only Oracle Linux is supported.
However Oracle VM can also support guest O/S installation in hardware virtualized mode (HVM), is this supported on Exalogic?
Unfortunately Windows cannot be deployed as "Guest OS" on Exalogic.
Some operating systems can be installed on a virtual server on Exalogic but (again) it's not the case of Windows. The 'Exalogic Guest Base Template' is built using Oracle Linux UEK 5u6 64-bit. No other Operating System can be installed on an Exalogic system. The Exalogic Guest Base Template is the only OS distribution that is supported, and all VM Templates and Virtual Assemblies that are deployed on Exalogic must be built using the Exalogic Guest Base Template. There is no automated way to upgrade non-Exalogic VM Templates or Virtual Assemblies so they can be deployed on Exalogic. Specifically: OVM 2.2-based templates, Solaris x86, Red Hat Linux, Windows, SUSE and other Linux distributions are not supported by Exalogic.
Also, note that only the version of Oracle VM provided with the Exalogic Elastic Cloud Software will function on Exalogic hardware. No other hypervisor is supported.
Hope this helps.