On May 23, 4:14  䮮
> Hi all
> I'm running on my machine vindows vista home and ajust can not install
> ruby 1.8.7 or 1.9.1 on my machine.

Did you use the installers from here?

http://rubyinstaller.org/

Did you check the option during installation to "Add Ruby executable
to PATH"?

> I used window-installer for this ruby release but after installing i can
> not install any gems like rails or wxruby . After tipping in cmd : gem
> install rails,it sais gem is not a internal or external command.

I'm not aware of any Window-installer, you refer to RubyInstaller?
Please see my previous comment about the lack of checking the box
during installation.

Even if you don't added to the path, you can start a personalized
command prompt from the application folder named "Command Prompt with
Ruby 1.8.7"

HTH,
--
Luis Lavena