Two ways to Over come this problem!
1) Completely remove internet connection from your Personal system, or turn on the Air-plane mode in our laptop and start your Cisco Tracer Packet software it will not ask the login instead it will allow the user to use the application.
The main factor is that you don't allow the Cisco packet tracer to access internet and ask for the login.[N B : I think the software developers had given access for a plain computer i'e computer machine not connected to web wide web]
2) Block the internet access to the Cisco Packet Tracer ..
Even though you are connected to internet the cisco packet tracer software thinks it has no internet connection and we will grant access to the user.
For windows I can help to follow the procedure to block the internet access.
1) Click the start button.
2)Search for the "Security" keyword.
3)Click on "Windows Firewall with Advanced Security".
4)Click on "Inbound Rules"
5)Again right click on Inbound Rules a mini tab appears and click on "New Rules".
6)New Inbound Rule wizard will appear in that select "program" and click on the Next button.
7)In "This program path" browse the Cisco packet tracer file in your computer, open the bin folder and finally click on the packet tracer application and then click next
click Next for two times.
9)Finally give an name and click finish.
done. Hope it helps and thank you!
