mysql installation in Windows 7

I have Windows 7. I am trying to get the gem installed for MySQL
Server 5.5
So, I get the zip file for gem from Brian Mario’s repository on github
mysql2, extract it in the new mysql2-0.3.12b5 folder and start the
procedure as follows. As seen below, I get the error “file 'lib' not
found” at the end. I tried many times, got the same problem. Anyone
has a solution to this?

EDZIBA-PC
/c/railsinstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.12b5
$ gem build mysql2.gemspec
fatal: Not a git repository (or any of the parent directories): .git
fatal: Not a git repository (or any of the parent directories): .git
WARNING: no description specified
  Successfully built RubyGem
  Name: mysql2
  Version: 0.3.12b5
  File: mysql2-0.3.12b5.gem

EDZIBA-PC
/c/railsinstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.12b5
$ subst X: "C:\Program Files\MySQL\MySQL Server 5.5"
Drive already SUBSTed

EDZIBA-PC
/c/railsinstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/mysql2-0.3.12b5
$ gem install mysql2-0.3.12b5.gem --platform=ruby -- --with-mysql-dir=X:
--with-mysql-lib=X:\lib
Temporarily enhancing PATH to include DevKit...
Building native extensions. This could take a while...
Successfully installed mysql2-0.3.12b5
1 gem installed
Installing ri documentation for mysql2-0.3.12b5...
file 'lib' not found
Installing RDoc documentation for mysql2-0.3.12b5...
file 'lib' not found