Cygwin always has older git (right now it has 1.7.9 released in May/2012. This needs an update to get around with has some unicode problems.)
Let's say a Windows junk was thrown at you. Git was not in that box. When you start looking at "msysgit", "Git for Windows", "Tortoise Git", "SourceTree" and "Github for Windows", you notice that they have all different git versions. Installing them, then you will end up with