OT: WinZip question

[good-dog at northshore.net]

All;

What's the deal with WinZip?  Is it the equivalent of StuffitExpander 
for Windows? Does it come as a standard app with Windows?  Or is it 
something you must buy?

A friend of mine, very computer unsavvy but learning, is on Windows and 
wants to buy something that requires Acrobat and WinZip.  He can't 
figure out if he has it on his system or not, and I'm not there to take 
a look at his computer.  I'm trying to figure out if it's most likely 
there or not.

Can any of you cross-platform dressers help me out?

Thanks.

Mark