Interesting this. I have been trying to open a Windows file that came down with a 356mb download into the .rar format and sits nicely there as a pile of books. From there you 'extract' to the original file which is where the Windows setup file then is.
The windows file as the setup file is supposed to download to the device (in this case a sat-nav) but all it does releases the extractor and then freezes - not the pooter tho.
Very frustrating.