Problem to install Scrum plugin

After installed bitnami-redmine-2.6.4-windows-installer, I tried to install Scrum, but failed. Appreciated your help.

F:\Redmine\apps\redmine\htdocs\plugins>rake redmine:plugins:migrate RAILS_ENV=pr
oduction
(in F:/Redmine/apps/redmine/htdocs)
rake aborted!
You have already activated rake 0.9.6, but your Gemfile requires rake 10.4.2. Pr
epending `bundle exec` to your command may solve this.
F:/Redmine/apps/redmine/htdocs/config/boot.rb:6:in `<top (required)>'
F:/Redmine/apps/redmine/htdocs/config/application.rb:1:in `<top (required)>'
F:/Redmine/apps/redmine/htdocs/Rakefile:5:in `<top (required)>'
(See full trace by running task with --trace)

I also tried below command:
F:\Redmine\apps\redmine\htdocs\plugins>bundle install
Fetching gem metadata from https://rubygems.org/.........
Using rake 10.4.2
.....
Your bundle is complete!
Gems in the groups development, test and sqlite were not installed.
It was installed into ./vendor/bundle

It looks some configuration error, unfortuntely I have no idea how to fix it as I'm a PM not a techinical person. Your help is much appreciated. Thank you.