Eu instalei o Ruby 1.93 no meu windows 7 PC usando o instalador de um clique do Ruby 1.9.3-p194. Eu posso usarruby comando para interpretar arquivos, mas quando eu digitoirb isso me dá o seguinte erro:

C:\Users\Acer>irb
F:/Programs/Ruby193/lib/ruby/site_ruby/1.9.1/rbreadline.rb:2111:in `expand_path': non-absolute home
(ArgumentError)
        from F:/Programs/Ruby193/lib/ruby/site_ruby/1.9.1/rbreadline.rb:2111:in `_rl_read_init_file'

        from F:/Programs/Ruby193/lib/ruby/site_ruby/1.9.1/rbreadline.rb:2094:in `rl_read_init_file'
        from F:/Programs/Ruby193/lib/ruby/site_ruby/1.9.1/rbreadline.rb:2515:in `readline_initialize
_everything'
        from F:/Programs/Ruby193/lib/ruby/site_ruby/1.9.1/rbreadline.rb:3746:in `rl_initialize'
        from F:/Programs/Ruby193/lib/ruby/site_ruby/1.9.1/rbreadline.rb:4758:in `readline'
        from F:/Programs/Ruby193/lib/ruby/site_ruby/1.9.1/readline.rb:40:in `readline'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/input-method.rb:115:in `gets'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb.rb:139:in `block (2 levels) in eval_input'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb.rb:273:in `signal_status'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb.rb:138:in `block in eval_input'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:188:in `call'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:188:in `buf_input'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:103:in `getc'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/slex.rb:205:in `match_io'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/slex.rb:75:in `match'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:286:in `token'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:262:in `lex'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:233:in `block (2 levels) in each_top
_level_statement'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `loop'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:229:in `block in each_top_level_stat
ement'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `catch'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb/ruby-lex.rb:228:in `each_top_level_statement'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb.rb:155:in `eval_input'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb.rb:70:in `block in start'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb.rb:69:in `catch'
        from F:/Programs/Ruby193/lib/ruby/1.9.1/irb.rb:69:in `start'
        from F:/Programs/Ruby193/bin/irb:12:in `<main>'

Eu instalei o Ruby noF:/Programs/Ruby193 pasta e adicionadoF:/Programs/Ruby193/bin no meuPATH. Eu também tentei com o Ruby 1.87, mas recebi o mesmo erro.