can't play the game, it either locks down or plays music while the screen goes black.

Similiar issue here: The game installs, loading bar appears and finishes, I can hear the intro video playing in the background but no picture is shown and the screen just stays black. Pressing buttons or clicking will not allow me to skip the intro and the game shows as "not responding" in windows XP AND Vista Ultimate.

I had this problem as well, fixed by reinstalling the game into a separate games directory (and not under Program Files). Example: C:\Games\GOG\CTP2
I've used this fix for some other games that don't behave in the Program Files folders. Hope this helps!

thank you very much, will try it soon and see if it works.

I'm experiencing the same problem (vista ultimate) and I have tried both moving the save location to another folder (heck even a different drive partician) and also the Apolyton unofficial patch and neither has worked sadly.
I get the same - loading bar appears but videos do not display, barring the audio and nothing else happens.
edit - I've sent a report to GoG so I'll wait and see what they say - if anyone else gets a reply a post here would be helpfull

Just repeating from another thread:
My issue: Game starts, loading message. Minimizes when playing the video. Click to bring it back up, video doesn't display properly and then appcrash message appears. Press close program but the game still runs and you can interact with menu buttons, albeit with distorted visuals.
This is how I avoid the crash message, which keeps the menu clean:
I start the game, the loading bar comes along. While that is happening I press escape continually so the game immediately skips the intro video and goes straight to the menu screen.
Not the best solution but it does avoid the issue for me.

I found a fix... the problem is the video files in game (namely the intro video and possibly the wonder of the world videos).
Go to your file browser where you installed the game. I.e.: D:\games\call to power 2\ctp2_data\default\videos ... (not sure what the default directory as I installed to a custom directory)
In there you will see a bunch of video files... cut those and paste them into a temp folder (dont delete them). Now launch the game.. it should work now (it does for me).
I tried re-installing the wonder of the world videos, but after I build them and the video tries to load, the game crashes... so just remove the videos and when the game tries to find the videos and can't find it, it ignores it and just continues to let you play. Works great for me.
You can always view the video files in windows media player outside of the game if you want to see them.
Hope it helps.

I'll give that video thing a try. I suspect this is one of those video codecs supports that microsoft lost (I seem to recall a reasonably major older video codex was lost a year or two ago). Either microsoft wouldn't pay or the company charged to much for an older codec - so for modern users its no problem but for quite a few older games it has totally hacked away the video.
I seem to recall you can get it independantly from the company but that its cost to the consumer was very steep.
Edit its not the video codec - they play perfectly in WMP (windows media player) although I note that ffdshow is active to play them.
edit 2 - removing the videos does let the game work (for me at least) goes straight to the main menu without any problem. Not to get music to work (and yes I've tried the trick mentioned in the music thread with no luck)

Had this same problem. I found that CtP 2 doesn't like 64-bit. Fortunately, I also had 32-bit Vista installed. Game worked on the first try in 32-bit. Didn't have to mess with any compatibility modes or anything.

MS removed support for Indeo in versions of Windows starting with SP1. So, if you're needing to use those, then you are stuck buying a copy for $15 from the owner, and they don't offer a trial or refund. So, you can reasonably end up paying for something that doesn't solve the problem.