Strange LoadError on Windows

[revskill10]

Hi, i'm using DataMapper with Postgresql on Windows XP for development. Ruby 1.9.3 with RubyInstaller. The setup is normal, there is no error in loading gems.
But when i run the same setup on Windows Server 2008 machine, do_postgres can't be loaded. The error is here:

E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/do_postgres-0.10.12-x86-mingw32/lib/d
o_postgres.rb:31:in `require': 126: The specified module could not be found.   -
 E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/do_postgres-0.10.12-x86-mingw32/lib/
do_postgres/1.9/do_postgres.so (LoadError)
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/do_postgres-0.10.12-x86-
mingw32/lib/do_postgres.rb:31:in `rescue in <top (required)>'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/do_postgres-0.10.12-x86-
mingw32/lib/do_postgres.rb:26:in `<top (required)>'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-postgres-adapter-1.2.
0/lib/dm-postgres-adapter/adapter.rb:1:in `require'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-postgres-adapter-1.2.
0/lib/dm-postgres-adapter/adapter.rb:1:in `<top (required)>'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-postgres-adapter-1.2.
0/lib/dm-postgres-adapter.rb:1:in `require'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-postgres-adapter-1.2.
0/lib/dm-postgres-adapter.rb:1:in `<top (required)>'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-cor
e/adapters.rb:163:in `require'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-cor
e/adapters.rb:163:in `load_adapter'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-cor
e/adapters.rb:133:in `adapter_class'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-cor
e/adapters.rb:13:in `new'
        from E:/dungth/Ruby193/lib/ruby/gems/1.9.1/gems/dm-core-1.2.0/lib/dm-cor
e.rb:230:in `setup'

Do you know why is this error and how to fix it ?
Thank you very much.

[dbussink]

Haven't seen this error before, but have you also installed the postgres dll files? After installing the gem it should print instructions on how to do this.

[lgulliver]

I get this on Windows 8 as well, with the same error.

I have the postgres DLLs all in the right places, but the error is still present even with it setup in the PATH.

[xpentor]

I have this error as well in Windows 7 and I have all DLLs in the right places. frustrating!

[dbussink]

Biggest problem here is that I don't have access to any Windows machine to check this issue.

Googling for similar issues does seem to point at DLL loading issues with other native libraries:

http://stackoverflow.com/questions/5164818/loaderror-trying-to-use-mysql-with-ruby-on-rails-in-windows-rubymine-ide