ruby on rails when making new app it says unknown encoding name . on windows 7, rails 4.2

when I type "rails new ..." it goes well until it reaches:

run bundle install

C:/RailsInstaller/Ruby2.2.0/lib/ruby/2.2.0/win32/registry.rb:71:in `find':unknown encoding name - CP720 (ArgumentError)

I have already changed the encoding name by " chcp 1252 " which I found in another answer rails4 unknown encoding name - CP720 , because it was giving me " unknown encoding name - CP720 (ArgumentError) " when I was trying to know the version of the rails through " rails -v "

If anyone knows how to solve this please tell me , and if you need more information tell me what you need to know and I will type it in a comment .

Thank you very much .