Running vista64 with saitek x52 system, every time I try to start the game I get as far as the title screen then game stops with message
Debug Fatal Unable to register Apache Havoc: No_Dplay_Error_message_Found.
I have tried running it under all compatibility modes, tried it with x52 connected and disconnected, tried running as administrator all to no avail always get the same message.
Any help gratefully received

That explains why I want to find it, but now I have found it is there anything I can do with it to get this game running.
I was wondering that if I download EECH whether it would somehow ( perhaps magically, who knows?) integrate with apache v havoc even though apache isn't working on this computer.
Edit: Just downloaded EECH and have exactly the same problem...this sucks

This is a shot in the dark but try it anyway. Uninstall the game and reinstall it to a folder not in program files, something like C:\games\enemy engaged. When you install it make sure that your virus scanners are off, you run the installer with admin permission and if you can, run the insall in windows xp compatibility mode.

It was certainly worth trying, but you can guess what I am going to write next.
Has anyone got this running on vista 64 and if so how?
I also tried the all mods tip again with EECH but no joy , still the same error.

Because I do not have a 64bit Vista and the game launching problem, I can not test that myself however I created a dll which replaces the DirectPlay with minimal stub. That stub ignores the application registration calls and provides no networking. On my system the game starts with it (obviously without any networking capability) although in my case it also works with the real one so there might be different problem.
If you want to test it, you need to do following:
1) Download this rar with the dll.
2) Unpack that dll (dplayx_emu.dll) into the directory where the original dplayx.dll resides.
3) Inside the registry change references from original dplayx.dll to the dplayx_emu.dll.
On 32bit Vista they are stored in following two registry keys:
HKEY_CLASSES_ROOT\CLSID\{2FE8F810-B2A5-11d0-A787-0000F803ABFC}\InProcServer32
HKEY_CLASSES_ROOT\CLSID\{D1EB6D20-8923-11d0-9D97-00A0C90A43CB}\InProcServer32
On 64bit system the path might be slightly different.
4) Try to run the game.