When I type
gem install sass
I get the following error message
C:>gem install compass ERROR: Could not
I also noticed issues with rubygems.org yesterday (in one environment), but your error almost sounds like an issue with a newly-installed Ruby and its SSL integration/configuration (having it locate SSL during installation, as well as the necessary certificates).
You might check out:
SSL Error When installing rubygems, Unable to pull data from 'https://rubygems.org/
But if that doesn't help I recommend continued searching, as this seems to be a common problem area.