EC2 connection error in particular zones viz. Canada. Ireland and Mumbai

I figured it out.
Whenever using a previously ever unused key to make an instance, it shall be first kind of activated by running the following command from a mac or linux command line.
Go to the path where the '.pem' file for the key is kept and run

chmod 400 key_file.pem

Then freely use this key and any '.ppk' file generated from it to connect from windows.