Hello,
I just installed and tried to play MM7 on my desktop (i5 760, GTX 560, windows 8.1) and ran into a huge problem.
The game runs at about 15 FPS. I installed the GrayFace patch but it's the same problem. I then ran the setup and saw that hardware acceleration is unavailable. Searched through the forums and only found some topics that advised to change a registry setting 2dacceloff to 1 (which it already was). Then I tried putting all the executables and setup to windows XP compatibility mode and ran the setup again. It now allows me to run the game with hardware acceleration, but I think it still doesn't work as the fps is still the same. I also tried installing directX 9 manualy, but that didn't help either.

I have the same version of the game on my very slow laptop that has windows XP and the game runs at 60 fps flawlessly. Please help :D

Edit: I should also add that I played MM VI just before this and it ran fine too (in fact, It ran too fast and I couldn't limit the fps so I put the computer into power saving mode every time I played it)

Edit2: I just realized that I had the same problem running Unreal. On windows 7 it was fine, but on windows 8 it ran at very low fps until I installed a patch that allowed it to run in directX 10 mode. Might be the same problem.

Edit3: I just found a fix. After searching countless topics on how broken windows 8 support of older games is, I stumbled upon this topic http://www.blitzbasic.com/Community/post.php?topic=99477&post=1202630.
I downloaded the custom directdraw dll for windows 8, put it in the game's folder and it runs without slowdowns (though I cannot view the exact fps now).

Edit4: There is a downside to using the same fix (with the dll). You cannot force any options on the game through control panel (like AA or vsync - and I do have tearing in the game) or as I already mentioned, view or limit the FPS through third party software.

Yes that's the one. Thank you.

Also note that this solution will probably work for more games on windows 8 (as the fix isn't MM specific at all).

I've not had a problem with M&M7 under 8.1x64 at all. In fact, I have actually found it to be more compatible with older games than was the case for me with Win7x64. Have you installed DX9.0c into your Win8 installation yet? If not, that might be your problem. You need to download Microsoft's DirectX runtime for June2010 (the last and newest release of DX9) and download it and install it--you *do not* run dxwebsetup.exe, as that will tell you that you don't need it and won't install it--instead, run dxsetup.exe and it will install and you can actually watch as it installs the DX9.0c files that you don't presently have in your system. Installing DX9.0c is perfectly safe--it does not overwrite any newer version of DX, like DX10 +, for instance. This is a *must* for game compatibility with any post-WinXP OS.

That's exactly what I did. And it didn't help.

I haven't had any problems on windows 7 with old games, but on win 8 some of them run really slow (I had 64bit versions of both).

Edit: And another problem I had with the game was. It ran fine, but from time to time, the fps just dropped and at certain locations I would get like half the fps, but a restart would fix it. I found out I also had to go to nvidia control panel and set the graphics card to run in maximum performance mode. Apparently MM7 drew so little power that the program underclocked the card automatically, but then wouldn't sometimes undo it even when needed. But this is unrelated to the problem I had in the first place (the game would still run bad if I undid the DLL fix).

I *surely* wish I could help as I'm not having any of the problems you allude to in Win8.1x64 with *any* games, really--I feel certain you are using the latest Gog-installer version of M&MVII--the 2.xxx installers, as there are changes to certain of the launcher files that make the game fully compatible with Win8.x--whereas the 1.xxx Gog installer versions were much more difficult to get running in Win8. Also, there's a very simple way to run the game under 3d acceleration in Win8.1 without editing the registry at all--I've written more than once about it in earlier threads in this forum...

Are you by any chance running a laptop of some kind? I ask because if not, if you are running a desktop, then it should be fairly easy to get this game up and running perfectly for you under Win8.x. Laptops, unfortunately, are not so straightforward as desktops because they all too often use *custom* hardware components with non-standard device drivers, and that's why some laptop gpu drivers cannot be downloaded direct from nV or AMD, for instance--you have to go to the laptop OEM site for your gpu drivers, etc--that often simply don't work correctly with many games. Of course--the unwary laptop customer is never *told* of this and has to discover it through experience....;/

If you're still having these problems and you are running a desktop I can help and will be glad to if you need it...;)

The problem is solved (as hinted in the title). Just to recap though - I downloaded the game... around a month ago using the gog downloader manager, not the default installer. It should still install the same version I think.
There's other people with windows 8.1 that don't have the problem with old games, however I do. It's the same problem with Unreal, or with Stronghold crusaders - the fix I used for MM7 - that is, copying the provided library into the game's folder - works for all of these games.

My PC is a desktop . I also got the hardware acceleration going by simply setting the configuration executable to 16bit color mode (it's not even required to set the main executable to the same mode). The last problem where in certain situations my FPS would drop again because the graphics card was so underutilized was, again, easily solved in the nvidia control panel by setting the "Power management mode" to "Prefer maximum performance".