Bad news: There isn't a fix.
I have been playing WH40k:CG since it came out for the PC, oh 5 years ago or so. Being a fan of the tabletop game, I found this a great fix for my 40k addiction when no one was around to play the real thing.
While the game had always been buggy, I had found most the time a good reboot would get it running right again. Additionally, the last patch made by Random Games (version 1.2) seemed to right alot of wrongs. In fact, I had it loaded on a couple PCs in my home that were on a network, and played some Multiplay with a couple friends and some family. It was a glorious day for the world of 40k computer games!
All good things come to an end though...
In late 2002 I repartitioned my HDD and reloaded it with WinXP Pro. I immediately started reinstalling all my favorite games. Of course, one of the first to get loaded was Chaos Gate.
I started a new campaign, arranged my Tac squad, equipped them, and jumped into the first mission, the 'artifact recovery at the forest temple' mission.
I moved my squad around to my liking, put them in overwatch, then hit the "End Turn" button. The evil Chaos Cultists started moving in, while getting blistered by a hail of bolter-fire. One of the Cultists made it to within firing range of his Laspistol, then the unthinkable happened.... a screen refresh with no error message and I was staring at my desktop.
Thinking this was just some random buggyness I started up the game again and went through all the motions I just did. Once again, when a Cultist came within range of his Pistol and opened fire, I was taken bounced back to the desktop.
Thus began my quest to get Chaos Gate to work on Windows XP. I have tried the following with NO success:
-Rebooting
-Uninstalling/Reinstalling countless times.
-Running the basic install at version 1.0.
-Running patch version 1.1 only.
-Patching to version 1.2.
-Running in Compatibility mode for Windows NT/95/98/ME/2000 (none worked).
-Looking for NT compatible patches (there are none).
-Scouring message boards and support channels/websites.
I did find out some things though. SSI has been bought by Ubisoft. Ubisoft doesn't even acknowledge the existence of Chaos Gate. Random Games isn't even on the radar anymore. Forget getting any offical support.
About 6 months ago someone put some info on a web message board basically stating that the game was not designed to work with the NT Kernel, and had known issues with NT 4.0 and Win 2000 (they had some programming background from the content of the message). The kernel for XP and 2000 are very similar, and upon reading this, my hopes were dashed.
But all was not lost...
About a month ago, I bought a new computer desk, and setup an older machine to do some studying with. As part of the computer's setup, I installed XP and as a shot in the dark, I installed Chaos Gate. It seemed to work! I was delighted to no end, and after my studying was complete, I began a new campaign in earnest.
I got all the way to Kimmera IV (I think), where you can choose to pursue secondary objectives. One of the side objectives is to attack a machine world to secure some supplies. The map is set in an Industrial setting, randomized with about 4 Chaos squads to contend with. Then the crashing started again. It was the same thing, as soon as a Cultist got within pistol range and fired, I was dumped, with no warning or error, to my desktop.
I tried reloading the game, but the same thing persisted. When a Cultist shoots a pistol on a industrial setting map, the game crashed.
Well, having come this far, I took some drastic measures. I deleted the existing partition on the old computer's HDD, partitioned the disk in half with FAT32, and loaded Windows 98SE. I got all the drivers for the machine, loaded Chaos Gate, and have only a few missions to go before I finish the game. It still locks up from time to time, but as I mentioned earlier, on Win98, a reboot fixes all ailments. Eventually, I will partition the other half of the Hard Disk with another FAT32 partition, and dual boot WinXP Pro on the second partition.
Like I said, pretty drastic. I work on computers for a living, so this is stuff that I can do easily to get this game to work right. For a less literate computer user, who has XP and can't downgrade because their new computer has no backwards compatibility, playing Warhammer 40,000:Chaos Gate is not an option.