Fonts that are not native always seem to have issues for me on Windows if they are not big enough.
The best option is usually to use a native font like Calibri or some of the many other fonts that windows comes with or increase the size of the font quite a bit.
The font your using looks kind of bad to me on my linux box because it seems more geared towards headings and larger font sizes because of how condensed it is.
You may want to consider one of the more used but good looking fonts like PT Sans or Open Sans
In case my comments - or more likely my design - didn't give it away, I'm absolutely not a designer. Open Sans was a great tip, and the point about condensed versus paragraph text was eye opening. I've basically applied those points now, I haven't tested on a windows box yet but hopefully it's more legible.
Thanks for the 5-minute font picking lesson guys :)
