Redmine

I've followed this guide, Installing Redmine on Windows Server 2008 R2 and Apache w..., and in Step 1 of the Setting up Thin as a Windows service and configuring Apache section I receive the following.

D:\>cd D:\redmine-3.2.3

D:\redmine-3.2.3>thin start -e production -p 3000
Using rack adapter
WARN: Unresolved specs during Gem::Specification.reset:
daemons (>= 1.0.9, ~> 1.0)
WARN: Clearing out unresolved specs.
Please report a bug if this causes problems.
D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.12.5/lib/bundler/runtime.rb:35:
in `block in setup': You have already activated rack 2.0.1, but your Gemfile req
uires rack 1.6.4. Prepending `bundle exec` to your command may solve this. (Gem:
:LoadError)
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.12.5/lib/bundler/r
untime.rb:20:in `map'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.12.5/lib/bundler/r
untime.rb:20:in `setup'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.12.5/lib/bundler.r
b:95:in `setup'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/bundler-1.12.5/lib/bundler/s
etup.rb:9:in `<top (required)>'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:12
8:in `require'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:12
8:in `rescue in require'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:39
:in `require'
from D:/redmine-3.2.3/config/boot.rb:4:in `<top (required)>'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:12
1:in `require'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:12
1:in `require'
from D:/redmine-3.2.3/config/application.rb:1:in `<top (required)>'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:12
1:in `require'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:12
1:in `require'
from D:/redmine-3.2.3/config/environment.rb:2:in `<top (required)>'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:12
1:in `require'
from D:/Ruby22-x64/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:12
1:in `require'
from D:/redmine-3.2.3/config.ru:3:in `block in <main>'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rack-2.0.1/lib/rack/builder.
rb:55:in `instance_eval'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rack-2.0.1/lib/rack/builder.
rb:55:in `initialize'
from D:/redmine-3.2.3/config.ru:1:in `new'
from D:/redmine-3.2.3/config.ru:1:in `<main>'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thin-1.7.0/lib/rack/adapter/
loader.rb:33:in `eval'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thin-1.7.0/lib/rack/adapter/
loader.rb:33:in `load'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thin-1.7.0/lib/rack/adapter/
loader.rb:42:in `for'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thin-1.7.0/lib/thin/controll
ers/controller.rb:170:in `load_adapter'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thin-1.7.0/lib/thin/controll
ers/controller.rb:74:in `start'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thin-1.7.0/lib/thin/runner.r
b:200:in `run_command'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thin-1.7.0/lib/thin/runner.r
b:156:in `run!'
from D:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/thin-1.7.0/bin/thin:6:in `<t
op (required)>'
from D:/Ruby22-x64/bin/thin:23:in `load'
from D:/Ruby22-x64/bin/thin:23:in `<main>'

After receiving this error message the first time i installed the rack 1.6.4 gem, but I'm still prompted with the above. Please assist!