Remarks
For security reasons, it is often desirable to keep ethernet/token ring addresses on networks from becoming available outside a company or organization. In Windows XP/2000, the UuidCreate function generates a UUID that cannot be traced to the ethernet/token ring address of the computer on which it was generated. It also cannot be associated with other UUIDs created on the same computer. If you do not need this level of security, your application can use the UuidCreateSequential function, which behaves exactly as the UuidCreate function does on all other versions of the operating system.

In Windows NT 4.0, Windows 95, DCOM release, and Windows 98, UuidCreate returns RPC_S_UUID_LOCAL_ONLY when the originating computer does not have an ethernet/token ring (IEEE 802.x) address. In this case, the generated UUID is a valid identifier, and is guaranteed to be unique among all UUIDs generated on the computer. However, the possibility exists that another computer without an ethernet/token ring address generated the identical UUID. Therefore you should never use this UUID to identify an object that is not strictly local to your computer. Computers with ethernet/token ring addresses generate UUIDs that are guaranteed to be globally unique.