Vista themes

[asyluM]

Hey guys,
I'm getting kinda sick of the stock Windows Vista theme and feel like a change.
I've headed over to deviantart, downloaded some themes but they seem to be saved as files other than .theme.
I've seen one I like but don't know how to use it. Is there a way to install the theme?
Or, does anyone know where to find cool vista .theme files from?
Thannnnnnnnnnnnnkkkkkkssssssss.
asyluM