I have tried everything like going to the .idlerc folder and making changes, but nothing worked. Finally, I had to change the original config files and it worked because Python is assuming that another theme which I put under 'IDLE Classic' is the original one. Also, the key for run-module(F5) doesn't work. In the original config file, the key for run-module is <Key-F5>. However, Python does not read only that particular line and in the configure IDLE it shows that the field for run-module is empty.