Diablo Backwards Compatibility Guide

[Slayer_X64]

Hey community,

Thanks for useful the post, the registry trick is definitely the cleanest solution; unfortunately it didn't work for me at first, because the ID of my Diablo.exe didn't match the one provided by Blizzard.

Here's how to generate the ID of any game:

1. Run Diablo (or whatever game has a palette problem) in Compatibility mode WinXP SP3 (other modes might work, but I tested only this one) and just leave it right away. This will force DirectDraw to generate the ID of your game in a registry key named MostRecentApplication.

2. Find this key by running regeditit and browse your registry to:

For 32bits Windows: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
For 64bits Windows: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\DirectDraw\MostRecentApplication

Note down the value of keys "Name" and "ID" (make sure the Name is your game executable name)

3. The ID needs a little tweaking; let's assume it is 0x12345678. This is a 4-bytes long value, each bytes consisting of 2 hexadecimal digits, so read it as: 12 34 56 78. Because x86/64 CPUs use little endian, you need to reverse the byte order, in this case: 78 56 34 12.

4. Now to force DirectDraw into compatibility mode you need to create/update the key in (replace the final key name "Diablo109" by any name you need, it doesn't really matter):

For 32bits Windows: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\Compatibility\Diablo109
For 64bits Windows: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\DirectDraw\Compatibility\Diablo109

There must be 3 fields there:
- Flags (type: binary) = 00 08 00 00
- ID (type: binary) = the reversed value you obtained in step 3, in this example this would be 78 56 34 12
- Name (type: string) = the name you saw in step 2.

5. Test your game; if it works you should be able to remove any compatibility mode and play just fine!

Hope this helps, peace.

Z

EDIT1: Added reg path for win32bits
EDIT2: Added compat mode requirement to generate ID, and some more info about the registry keys

Just came back from a long absence, and I saw your post, and it reminded me of another solution I had found which I think addresses this issue:

First, download the direct draw compatibility tool from here(I uploaded it fresh just now): http://www.mediafire.com/?2vy9jbwwcl9nbo9

Run the direct draw compatibility tool, find the directory and the executable of the game you want to create a registry for. Select the "exe" file. Next click the "Create reg-file" button. After that, close the direct draw compatibility tool, go to the directory of the registry file you just created, and run it. after that is done, your game should run as intended.

I have to go through and revise the compatibility guide one of these days.