Check Hyper-V is the only one installed. See this list for IDs: https://msdn.microsoft.com/en-us/library/cc280268(v=vs.85).aspx

• IgnoreTheseRoleIDs - List of IDs that can be ignored|Integer

IgnoreTheseRoleIDs = ('20', '33', '67', '340', '417', '466', '477', '481', '487')

• None

• PASS
  No extra server roles or features exist

• WARNING

• FAIL
  One or more extra server roles or features exist

• MANUAL

• NA
  Not a Hyper-V server

• Hyper-V Host Servers

• Check-NameSpace