Here is the previous version of Strawberry Prolog:

Strawberry Prolog 2.91 for Vista/XP.exe (and for 98/Me)

Here you can download version 2.1 (the last version which supports Windows 95).

Download the following file:
StrawberryProlog2_1.exe (1 Mb)

(Version 2.1 is very early version and we don't recommend it for use).

Here you can download version 0.6 (the last version which supports Windows 3.1).

Download the following file:
Prolog16.zip (0.2 Mb)

You have to create a folder and to unzip in it. To start the compiler run prolog.exe.
(Version 0.6 is very early version and we don't recommend it for use).