Unable to install Rails

Hello,

I'm currently encountering a strange issue when I’m trying to install
Rails for a new project. I’d like to work with the latest versions, so
this is my initial starting point:

C:\Windows\System32>gem env
RubyGems Environment:
  - RUBYGEMS VERSION: 1.7.1
  - RUBY VERSION: 1.9.2 (2011-02-18 patchlevel 180) [i386-mingw32]
  - INSTALLATION DIRECTORY: C:/Ruby/1.9.2/lib/ruby/gems/1.9.1
  - RUBY EXECUTABLE: C:/Ruby/1.9.2/bin/ruby.exe
  - EXECUTABLE DIRECTORY: C:/Ruby/1.9.2/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-mingw32
  - GEM PATHS:
     - C:/Ruby/1.9.2/lib/ruby/gems/1.9.1
     - H:/.gem/ruby/1.9.1
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://rubygems.org/

When I run the following command : *gem install rails* I receive the
error message:

C:\Windows\System32>gem install rails
Fetching: activesupport-3.0.5.gem (100%)
ERROR: While executing gem ... (Gem::FormatException)
    builder-2.1.2 has an invalid value for @cert_chain

Is this related to the H: directory in the GEM PATH? Or am I missing
something?