MS Entertainment Pack Puzzle Collection is still available for download on Microsoft Games Website. Depending on your browser theres a small difference in the downloading it's self but it's just like downloading any other file.
You might need third party software or file changes to run them depending on your hardware. This pack is meant for Windows 95.
EDIT:
You can download it from here (see the video description):
youtube.com/watch?v=Veu-kCfKQCk
Or from here:
coreduo.me.uk/microsoft-entertainment-pack-the-puzzle-collection-1997/
And the serial (product id) is 66460-442-0215222-85966.
Good luck.