/usr -> Program Files (hello spaces my old friends, you've come to break my apps again)
/var -> ProgramData (but no spaces here)
/home -> Documents and Settings
/etc -> Control Panel
Spaces are avoided on base Linux systems because they're clunky for terminals more than fear of outright breaking things. To the extent spaces there do break things, that also happens on Mac and Windows for the same reasons (hence ProgramData being conspicuously space-less).