Assuming you mean the Demo/Tryout version (actually 4.01 or 4.01b):
ftp://ftp.nhl.nl/Win32/utils/ps4try.exe
or
ftp://ftp.ugatu.ac.ru/pub/Soft/Adobe/Adob...shop/ps4try.exe
Possibly the last great art program that would run on Windows 3.1, as well as 95 (even supported long filenames on 95).
This version is only limited in that it cannot save or print. It doesn't expire after 30 days.