I recently encountered some issues with Sudden Strike 1 & 2 and after that with Blitzkrieg. [and Delta Force]
So after some researches, it seems that it's not really the fault of GOG but more on the side of Microsoft.
I'm using a Win7 64Bit that I just installed from scratch on a new hdd.
And it seems that Windows Games Explorer is messing a bit things when I want to launch a game.

The "explanations" :
So. In very "short" and badly explained. It seems that when I install a game, Windows adds it automatically into the Windows Games Explorer. And each time you launch a game who is in the Games Explorer, the Games Explorer tries to download things (news, updates, whatever). And here is where it's stuck to me : I use Kaspersky Internet Security who seems a bit paranoid. And it seems that it blocks the process of going online for the Games Explorer process (1), and so... the game doesn't launch, and there is a rundll32 process hanging there. This rundll32 is related to gameux.dll (= Games explorer) who tries to connect to the web but can't (certainly because of Kaspersky). And it doesn't give up, nooo, it's using a whole core of my processor wasting resources for nothing, and preventing the game to launch (because it can't gather the options online). If I want to play, I have to launch again the game, open task manager and kill the "ghost" game opened previously and the rundll32.

There are some solutions suggested online (see links) like :
- Rename the game's executable (2)
- Disabling Games Explorer to collect information/covers/updates... (3)
- Deleting C:\Windows\System32\Gameux.dll & C:\Windows\SysWOW64\Gameux.dll
- Renaming them
- Unregistering them (?)(don't understand really what this is, it's suggested here by qwadrwr)
- Denying access to gameux.dll (see here)
- Deleting registering entries related with GameUX (see here)(4)

Btw, I have made all the important windows updates just after the windows install. But concerning the "suggested updates" : none. I suspect there is maybe one who may help to solve this, but don't know which one : I have 64 pending, and with all the... potential crap microsoft suggest to install with this updates, I'm pretty reluctant to try them all :P
I'm thinking that because I never encountered the issue on my older harddrive (and I was already using Kaspersky), and I remember I made a lot of this suggested updates (I wasn't well informed at this time, don't judge me).
I noticed too that the version number of gameux.dll isn't the same between my dying drive (= the previous comp' I was using) and my current one :
Version 6.1.7601.17514 (current drive) (modified the 21/11/2010)
Version 6.1.7601.18020 (previous one) (modified the 07/12/2012)
But I don't know at all if this could be an explanation/solution.

I would like to keep my Kaspersky on (because of safety), and to be able to play games offline if I want. So, does anyone has any idea about how to solve this efficiently and in a "clean" way ? [And I'm not interested at all by using Games Explorer by the way XD]
Thanks in advance for any help :) And sorry for asking for help again :S

(1) Happened to me for Sudden Strike 1 & 2, Blitzkrieg (see link before), the only other one that I have installed for now is Rollercoaster Tycoon and it hasn't encountered the issue, but I think it's maybe because it's the french version.
(2) This works ! But... doing that for each game ? And what about nvidia configs who depends of game's executables names ?
(3) Of course the easiest, but didn't worked for me unfortunately.
(4) If I understand well it suppress the games

Links :
Here are my main sources :
- Windows 7 Game Explorer interfering with Game launching
- Starting games: Rundll32.exe goes to max CPU usage, loading stops
- Older games causes rundll32.exe to open and 100% CPU usage
- Why does “Windows Games Explorer” attempt to access the internet whenever I launch a game ?
- Windows 7 and old games
- Enable or Disable Game Updates in "Games Explorer"
- And my own experiment with Sudden Strike 1 & 2 (and Blitzkrieg btw)

Edit :
Found new links (but no new solution) :
- Painkiller: Overdose won't load due to Parental Control Error
- RESOLVE IT FINALLY! Game Explorer AKA rundll32.exe problem with Games!

When you say that (3) didn't work for you, do you mean that you chose to completely disable Game Explorer (from "Turn Windows Features on or off") and after doing it, Game Explorer still interferes?

I first followed this to disable every options who may go online. It didn't worked.
You're talking in : "Turn Windows Features on or off" : I can only disable "Games" (no explicitely "Games Explorer") which contains Minesweeper, etc... I tried to disable it, restarted my comp', and still have the issue :/

Thanks for reading my wall of text & trying to help ;)

Earlier GOG thread about this. It even has the same link. Took me a while to find it though.

This kind of manure is just why I turn more and more to Linux, which is not problem free either of course.

This is why I use macOS (formerly OS X) for all my day-to-day computing stuff. Never had any such issues pop up since I first started using it in 2004. I just put up with Windows so I can play those Win-only games, including many here on GOG. *shrug* I do wonder whether I'll bother to get another Winbox once this one is out of date, but that is still a good number of years away.

Nothing is problem free XD But I was sticking with windows for games, if it's more and more an hassle to make'em work... I'll turn into the linux side of the force. I wonder that too :S I let the default GOG path : C:\GOG Games\... This is really an issue with Microsoft, not GOG it seems. It's Windows Games explorer who... can't accept that you don't let him go online :P Okay, I used it : SOLVED.
I was reluctant and wanted to know before if there wasn't a "clean" way instead of dealing with the dll but well...
Now it works perfectly, thanks both of you for your help :)

Yeah sorry, should have mentioned that killing Game Explorer is the cleanest, and only reliable, way.

Glad you got things working. Happy gaming!

No prob' ;)

Yaaay ! Finally, it's awesome :D Thanks again :)

Sorry to bump a necro thread, but this same issue just suddenly started happening to my while playing Hitman: Blood Money. I've played it on and off for a month, but just today Windows started the nonsense of having the game hang while GameUX through rundll32.dll just sat there doing nothing. Running the BAT file is what fixed it. It's not fun having to run a batch file off the internet to solve a problem, but it worked for me, and no Russian spyware is currently on my machine that I know of. Thanks!

Yeah, it's not nice to have to do such a manipulation to be able to properly play, we do agree !
Glad this worked for you too :)

Not only does that batch file work like a charm, games actually launch much faster for me now.

I didn't notice any problems with this until a few days ago. Apparently, since Microsoft is dropping
support for Windows 7, they are phasing out games.metaservices.microsoft.com as well, which
is the service location for GameUX in the registry.

If you have Windows 7, then, starting in 2019, many old games will have a delay of 30 to 90 seconds when launching, and some old games, for example, “No One Lives Forever 2”, “Contract JACK”, “Far Gry ”will not install or run at all.
These problems arose for Windows 7 in 2019 in 2072 old games.

The reason is the “Game Explorer” system program, built into Windows 7

To stop the "Game Explorer" program, use the tool "Stop Game Explorer"
Stop_Game_Explorer_1_1.zip [remove spaces in this link]
h t t p : //www.mediafire.com/file/2mrtxy4eo4pmi2g/Stop_Game_Explorer_1_1.zip

There are two versions of the program in the archive: for 64bit and for 32bit (i.e., x86).
“Game Explorer” controls only those games whose names are stored in the GameUXLegacyGDFs.dll directory
The Stop Game Explorer program renames GameUXLegacyGDFs.dll files in the \ Windows \ System32 and Windows \ SysWOW64 folders in GameUXLegacyGDFs_OLD.dll with the Owner, all Users and Permissions of these files saved using the Trusted Shell utility: executing commands on behalf of the TrustedInstaller system entry

The program "Stop Game Explorer" works with system files, so use this program at your own peril and risk.
The program works with system files, therefore your Anti-Virus may block.

You can also use this tool to remove Game Explorer, read HELP
BLOCK_GameExplorer.zip [remove spaces in this link]
h t t p : //www.mediafire.com/file/24e176643j9cj2r/BLOCK_GameExplorer.zip/file

If you have Windows 8/10, then these problems will not be, because there Game Explorer is deactivated.