Gem

Uninstall gem from window from PowerShell.

ruby -e "`gem list`.split(/$/).each { |line| puts `gem uninstall -Iax #{line.split(' ')[0]}` unless line.empty? }"

can't find gem railties (>= 0.a) with executable rails

bundle install --path vendor/bundle

How to default GEM?

Example you need to default bundler version 1.17.2 and run gem list to see all gems.

sudo gem install bundler --default -v 1.17.2

How to remove Default Gem ?

Remove the version that you need to remove

rm bundler-2.1.4.gemspec