Just run it, and when you get to the options, there is an option to check for file integrity (at least there used to be on old installers).

I thought that was only for multi-file installations? This is just a single-file one. Maybe I should just dump all these installers and just redownload everything anyway to be safe.

I read that there's a nice script out there that pulls down and archives all your installers, so maybe that's the way to go.

There is some way to retrieve md5 checksums from GOG servers for the installer files, because the gogrepo.py tool does just that... I recall it was mentioned in some earlier discussions, but I don't recall where exactly.

Another option, I think, is that you try to extract your existing installer with innoextract or similar tool. If it extracts ok without errors, then your installer is ok. Naturally, of course, installing the game itself does the same, ie. if the installation completes ok, then obviously the installer was ok because it was able to extract all the installation files.

(I am giving this advice so that you could yourself check each and every installer you have yourself, without having to ask for md5 checksums from other people, one by one.)

When it comes to your filesystem corruption, that is exactly why I am currently into more advanced filesystems like btrfs or OpenZFS, as they have their own checksumming method, and you should be able to see afterwards if your files are still intact, and not corrupted, without having to rely on "external" checksums.

I would need to check, I thought all my old installers did this. Anyways, simply install them if there is any concern. Depends on how big they are, one file is going to take seconds to download, so might be simpler. There is gogrepo for doing downloads, I use browser myself and teracopy with check enabled to copy. I also recommend having several backups, at one of which should be away from your house. This way, if you lose one (or in real extremes all in the house), then you always have a good copy to go back to. Raid is also a helpful extra (does not replace separate backups!!) as that can handle a drive or two failing and rebuild.

Current file version is setup_empire_earth_gold_2.0.0.2974_(25522).exe, so gogrepo.py or gogcli.exe can't help you ... unless there is a non Gold listing and the file hasn't been updated.

A better solution for you perhaps, is to try my GOGPlus Download Checker program. That checks internal MD5 values, which should indicate whether your file is okay or not.

https://github.com/Twombs/GOGPlus-Download-Checker

https://github.com/Twombs/GOGPlus-Download-Checker/releases/tag/v2.2

I actually have that file, although it is quite old I see.

Running a sham256sum, I get the following:

sha256sum -b setup_empire_earth_2.0.0.14.exe
d2a7b852c3785c051ae6628db01b893f2850ba94984936c18ba085cdbfb1796f *setup_empire_earth_2.0.0.14.exe