GCW downloads that are (.rar) not (.zip)

[bobb]

I have tried renaming the file to (.zip), but winzip cannot unpack them.
Is (.rar) a different unpacking tool, which I don't know about? or am I being real stupid and missing something?

The cracks that I am trying to download are the B&W no-cd cracks in German & Spanish as I cannot get the UK/US crack to work.

Please help!
Thanks, Bob