What is the best way to Pack/UnPack Zip files programmatically.

I've used

oZip = CreateObject("XStandard.Zip")
oZip.Pack("C:\ZIP\*.*", "C:\ZIP\NEW.ZIP")

AND

oZip = CreateObject("XStandard.Zip")
oZip.UnPack("C:\ZIP\NEW.ZIP", "C:\ZIP\")

But I'm uncertain of this DLL.... is it available on all Windows machines, or would I have to distribute it?

Thanks,

dg