Install redmine 2.0.3 + mysql 5.5 in windows XP

1. download and install Ruby1.9, Rubygem, Ruby Dev, redmine2.0.3, Mysql 5.5
2. follow the instruction of install redmine
3. met issues
a) issue: can not connect the http://rubygems.org/              
    output:WARNING:  Error fetching data: SocketError: getaddrinfo:(http://rubygems.org/latest_specs.4.8.gz)
                ERROR:  Could not find a valid gem 'json' (>= 0) in any repository
    solution: set http_proxy=http://192.168.8.26:8080
b) issue: can't install json
    solution: install rubydev
c) issue: can't install mysql2
    output:Incorrect MySQL client library version! This gem was compiled for 6.0.0 but the client library is 5.5.20. (RuntimeError)
    solution:download and unzip libmysql.dll, copy libmysql.dll to rubin/bin directory.