Windows Script 5.7 comes with XP SP3, so if you are running XP SP3, Vista, or Server 2008, you already have WScript 5.7.
This is a relatively small upgrade compared to other releases but it does come with some performance improvements and bug fixes which are noted
here.
If you want to download Windows Script 5.7 for these older operating systems, go
here.
If you want more in depth information about this release, check out the KB article
here.