Hello, im new to GOG and i just bought Diablo but unfortunately im having issues. The game and the galaxy 2.0 both download just fine but when i open them it says its installing, the progress bar gets to 100% then i get the message shellexecuteex failed code 2 the system cannot find the file specified, Ive googled and troubleshooted and nothing works, can someone please point me in the right direction? Im on an HP laptop with windows 10 64bit

Close and uninstall Galaxy and download the 0.8 GB offline installer from your library instead.

I tried that and got the same results. It downloaded fine but wont open

Maybe there are still remnants of the incomplete installation through Galaxy or of Galaxy itself that prevent any further attempts?
Perhaps you'll have to get rid of those - if there still are any - first in order to proceed.

This could also prevent execution of the offline installer:
https://support.microsoft.com/en-gb/topic/what-is-data-execution-prevention-dep-60dabc2b-90db-45fc-9b18-512419135817

I also tried running all 3 options as admin and it says the files cant be found, I will try the info the link you posted now. I tried turnig off DEP and it wont let me, it just says sorry we ran into a problem. this is getting weirder. It just forced an update on me and i wasnt having issues before then.

If the files can't be found then it maybe hasn't downloaded the offline installer correctly or not at all.

Try and download the offline installer again but this time to a location other than on the C:\ partition, but D:\ or E:\ instead. When finished downloading, go to the location, find the 0.8 GB offline installer .EXE, and run it to install the game (also to somewhere else other than the C:\ partition where Windows itself is installed on).

Installing games to the same location where Windows itself is installed on often is responsible for all kinds of issues.

This may sound dumb, but have you tried rebooting your PC?
Can you install other things, like Firefox or some other random browser?

Can you provide the exact path of where you saved the installer? Copy the path from the address bar and paste it here. Alternatively select the Setup file and click "Copy path" in File Explorer's ribbon under Home.

Does your Windows username contain any non-english characters?

I'm starting to be inclined to agree with you that there is a problem with Windows because I had a game already installed on my computer that won't even open now and everything else on my computer is acting weird like it doesn't want to open. I'm going to try all of the different advice that has been given on here but I'm not a big computer guy and this is getting frustrating so I'm starting to wonder if just doing a factory reset and trying all over again will fix the problem

Yeah, that is a very weird error. If other things worked, we could try a few other things, but if games that previously used to work stopped working, then it may indeed be an issue with the OS.

Perhaps a Windows update failed and broke something for you. Try to check for new Windows updates. Try opening command prompt as admin and then run "sfc /scannnow".
There are other things to try, but if you have all your data backed up, it may be simpler to do a factory reset.

Yes I have rebooted several times now and I keep checking the status of the updates and it's telling me they keep failing for some reason so I'm just going to try the factory reset is nothing else seems to be working and I've been at this for hours so I'm pretty much at my limit

Ok, it took a factory reset to make it work but I can finally play my game, thanks everyone for the advice

Glad to hear that it got sorted in the end. Enjoy Diablo 1!

Feel free to check out the free game selection too!