Terminal and Control panel shows different version of ruby

问题

I type ruby -v and this shows

ruby version 2.1.5p273

but in my control panel, ruby version is 2.2.1-p85

I tried to change the version with rvm use ruby-2.2.1 in the terminal but it returns 'rvm' as not internal or external command.

I am using railsinstaller btw

来源：https://stackoverflow.com/questions/29691448/terminal-and-control-panel-shows-different-version-of-ruby