Funny you mention this, since I've noticed that even in ReactOS - which is supposed to be a Windows clone - there's something "not quite right" about it when you look at a screenshot like http://1.bp.blogspot.com/-SN0tgsoHkV8/UwMdmx3RM1I/AAAAAAAAA3... - I think it's mostly the fonts. I've found that free (as in freedom) fonts just have this... odd look to them.