If the uninventoried resource was a platform or top-level server, and it still exists and is running, it will show back up in your Auto-Discovery Queue the next time the agent runs a server-scan discovery (which by default happens every 15 minutes). You could then either IGNORE the resource in the auto-discovery queue, or COMMIT it back to inventory again. Note: if the server is not auto-discoverable (that is, you originally manually added it), it won't show up in your auto-discovery queue, but you can manually add it back to your inventory again.
If the resource was a child service, and it still exists, the next time a service-scan discovery is run (which by default happens every 24 hours), it will automatically show up back in your inventory.
Tnx dear, i've found what you mentioned .