editing high tones

I am using Windows 7 and Audacity 2.1.0 . Is it possible to tone down or cut off sounds that are too high or sound tinny?

The “Equalization” effect allows you to cut or boost frequencies: http://manual.audacityteam.org/o/man/equalization.html

You may want to upgrade. The current Audacity version is 2.1.2 from our official site http://audacityteam.org/download/.