Neither. You are supposed to buy a licence for either of them.
7zip is open source, available for virtually any platform and totally free. It can decompress any of the formats supported by the others. It can compress to zip and some others plus has its own superior compession format.
Forgot about 7zip - better compression .... but as fo3 says less widely accepted ... tends to be used by the techies and the game ripping types (as does uha)
I'd probably add a couple of other packages as well to make a solid compression toolkit .... but that's getting into quite specialist areas and needs.
for an all round winner my star would still be winrar.
it's ability to create grown up self extracting files is invaluable
Many thanks to you all, I will take the advice Given that it would seem to me to be the best Program, as I said earlier Its "Winrar for me"
Again 'Thanks to you all'
I personally prefer Winzip to Winrar, don't know why, I guess I just got used to it. I think both are good though. If you would like to get the archiver for free download Winzip here: http://freearchiver.org/
I use 7-zip at home by the way, it's rather good too.