Hello. I'm thinking about replaying Tex Murphy games. I played and finished Overseer in the past, but on my current OS (Windows 11 64-bit), I can't get the videos and music to work. There is a MPEG2 Driver Error at the beginning and there's nothing on the MIDI section (as far as I know, there should be Microsoft Midi Mapper). How to fix this?

On the pc gaming wiki entry for this game there seems to be mention of both issues and how to fix them.
pcgamingwiki on Tex_Murphy:Overseer

For the MPEG2 Driver issue. And for the no music issue.

Edit: It seems that the url link may appear broken due to some parsing error from the GOG editor (I think it does not like the intermediate ":"). But you can copy paste or google the pc gaming wiki entry.

Tried that (as well as few other suggestions from Steam forums), but unless I'm doing something wrong, so far no luck.

On my end, I actually receive a prompt asking if I want to use ffdshow after launching. I've found that this 'MPEG2' error appears if I choose not to.

Also, you might want to confirm that VirtualMidiSynth is working with other titles. In my case, I wasn't getting any audio even after everything was configured properly because Windows had changed my audio output device to my secondary monitor for some reason.

Overseer appears to be working with MUNT as well. In this case, select 'MT-32 Synth Emulator'.

I spent hours. trying to get the game working on windows 11. I finally did so I thought I'd leave a post here and save people the frustration. I had. First do not install ffshow that will just cause the game to crash to desktop. instead, after doing a clean install (use the backup installer not gog galaxy) and removing any codec.packs most guides tell you to use., set compatibility mode to windows vista. service pack 2. and run the game at the ffshow prompt pick run once. if all goes well the game will run and play video. you will still need dgvoodo and the no music fix. but after that the game worked for me.

I followed your advice and got the game to work again. Thank you so much!

This works very well and the game runs smoothly thanks The only other thing I did was run the dgVoodoo.cpl application go to Add and browse to where the Overseer folder is then click the DirectX tab and untick the dgVoodoo Watermark tab which removes it from the game windows. In Windows 11 you get a warning but you can safely ignore it

Ive done everything above and the Video runs but it is green and devided into 3 Videos :/

.
Actually, with Win11 and the no videos issue (mpeg2 error), you only need to (assuming you didn't junk it up from other stuff above):

1. Install using GOG Galaxy. (Also works with the offline installer IF that shows up after install with admin checked. I've seen it without that by doing nothing different and it may fail to work there that way for an unknown reason though that could also have simply been related to * being in place at the time.)

2. Go to the game folder and right click on OVERSEER.EXE the choose properties.

3. Click Change settings for all users and then uncheck Run this program as an adminstrator. Click OK and uncheck it again. Click OK.

(A possible problem with some GOG games where an error issue happens with admin use that causes the game to fail in some way as I noticed with a different one. Here it fixes the video issue.)

4. Run the game and choose use ffdshow always* and the videos work with no error there.

* Selecting don't show again with ffdshow can totally bork it** Best selection in game of the Xing mpeg and renderder of hardware of which both are already default. Not all variations tested.

** If previously selected don't show again choice can fix this by opening Windows registry, searching for "ffdshow" and deleting each and every entry for that since devs very sadly didn't clean remove that on game uninstall. Then once nothing more is found, reboot computer. I uninstalled the game beforehand and reinstalled after that but didn't test it in any other variation. Can also clean install Windows for those unable to do this (different user doesn't work). This gets the selection to show up again and can then pick a better choice where the videos play again.

You don't need to do anything else. This has working videos and working gameplay on Win11.

NO NEED TO TRY TO INSTALL THE POSSIBLE SECURITY RISK OF FFDSHOW MANUALLY OR ANYTHING ELSE IN POSTS ABOVE OR AS FOUND IN OTHER THREADS AS A FIX TO IT.

This doesn't fix any possible graphical issues (although the game seems to be still playable just fine enough for the first 3 or 4 locations that I tested with the issues present) and it doesn't fix missing music. I'm not playing or testing the game further so won't look into anything else.