Just bought the game obviously, as it's a new release.

Classic Installer files on the site are listed thus

Myst IV: Revelation (Part 1 of 7) 1.03 1 MB
Myst IV: Revelation (Part 2 of 7) 1.03 4 GB
Myst IV: Revelation (Part 3 of 7) 1.03 2.5 GB
Myst IV: Revelation (Part 4 of 7) 1.03 1 MB
Myst IV: Revelation (Part 5 of 7) 1.03 4 GB
Myst IV: Revelation (Part 6 of 7) 1.03 4 GB
Myst IV: Revelation (Part 7 of 7) 1.03 1 GB

After downloading we see two versions, and despite the sizes of the installers being

at 6.53 GB
setup_myst_4_revelation_1.03_(18900).exe
setup_myst_4_revelation_1.03_(18900)-1.bin
setup_myst_4_revelation_1.03_(18900)-2.bin

and at 8.95 GB
setup_myst_4_revelation_1.03_(21495).exe
setup_myst_4_revelation_1.03_(21495)-1.bin
setup_myst_4_revelation_1.03_(21495)-2.bin
setup_myst_4_revelation_1.03_(21495)-3.bin

Despite the 2.5 GB difference in installer sizes, both require 7.1 GB space on the install drive.
With little apparent difference to explain the need for two game versions presented as only one.

What's the reasoning behind this.

Looks like a simple error, possibly. The 8.95 GB set, 21495, would appear to be the latest version. Perhaps the first version is the original Windows version--people always clamor for the "original" version even if it *won't run* on their OS/hardware...;) Just a guess...

Well the only difference I can see is the (21495) asks me to select a language before installing.
Problem is that both fail to run, I get a splash screen with a loading bar then it CTD's as soon as I get a Black full screen Window.
Not tried to figure out why yet.

I'm downloading Myst IV (manual version) now...thanks for the input! I could have sworn I saw a *third* version number on a setup.exe a moment ago...;) I'll keep checking and report back...Have you tried a Galaxy install?

Edit1: I just thought of this...you might try renaming or removing the files you do not wish to install--as the setup exe might be trying to open the wrong .bin files...just a thought...still downloading here, but almost done.

Edit 2: Disregard what I said about a different version number thankfully--I didn't realize I had downloaded the files to my Myst III folder--so I saw that version number, too...;)

Edit3: Success! I moved the files from version 18900 into their own sub-folder, ran setup for the newer version--and it installed without a problem!

Success! I moved the files from version 18900 into their own sub-folder, ran setup for the newer version--and it installed without a problem!

i tryed doing this doesn't work it asking for the other .bin files

Moving files is simple, but not an issue and bins are selected by file name matching nothing more
Exe and bin files of the same name must be treated as one installer

eg
EXE
setup_myst_4_revelation_1.03_(18900)

will only load bins with that name e.g.
BIN
setup_myst_4_revelation_1.03_(18900)-1
setup_myst_4_revelation_1.03_(18900)-2

Remame it to whatever you want, e.g .Game, and as long as the bins are named the same the install runs normally
e.g.
EXE
Game
BIN
Game-1
Game-2

This works for all GOG games I've tried it with, so them being in the same folder isn't the problem, as they are named differently
I have no issues installing the game, it just isn't running properly, and I've been to busy to try and figure out why, just yet.

The 18900 version only contains English (or whichever language you chose on the dowload page) while the 21495 version has all of them.

Other than that, they're both the same 1.03 version that came out in 2005.

I just finished the 21495 download. I wish I knew that in advance LOL! Save 8 Gigs.