I've never used the native zip program in Windows but I have used both WinZip (which I prefer) and WinRar and have never had a problem using either of them.

I have Windows 7 on my laptop and WinZip works just fine when I'm transferring a zip over for on-the-road work.  Since the folder structure in Poser 8 is exactly the same as it is in Poser 7 you shouldn't have any problems using a 3rd-party program to unzip.  Like I said, I prefer WinZip and have been with them since ver. 4. 

Hugz from Phoenix, USA

Victoria

Remember, sometimes the dragon wins. Correction: MOST times.