The windows you say is the Ethernet I connect my PC and Robot after I minimize the HMI?
No, the PC connection has nothing to do with it. The KRC4 runs two OSs in parallel, Windows and VxWorks/KSS. The KLI is "owned" by VxWorks/KSS, and can only be modified through the KUKA HMI.
If you minimize the KUKA HMI, you are accessing the Windows side of the KRC4. Using the Windows Control Panel, you can change the IP of the Virtual Network connection between the two OSs (NEVER DO THIS!!!), but you cannot change the KLI from the Windows Control Panel.
I just want to know where can I change the internal ip address of Kuka.
Through the KUKA HMI.
But I just want to figure out whether I accidentally change the internal IP.
If you made a change using the Windows Control Panel in the KRC4, then yes, you changed the internal IP. Windows Control Panel has no access to the KLI settings.