I am using the Widescreen fix from Nemesis2000 you can find it at PCGamingWiki (scroll down to widescreen solution)
www.pcgamingwiki.com/wiki/Metal_Gear_Solid:_Integral

-Follow the insdruction for the Widescreenpatch (overwrite the ddraw.dll)
-Set mgsi.exe to win98 compatibility mode
-I am using a Tool called "Borderless Gaming" to get the game in fullscreen.
-done

Ah...so you did have to overwrite the ddraw.dll, Doesn't really say to do it or not on the PC gaming wiki game page.

I had this working fine yesterday, today I couldn't launch the game. Reinstalled it, and the Widescreen Fix is stopping the game from launching as soon as I overwrite the drawdll file. Anyhting really obvious and stupid I'm doing wrong?

does the patch stretch the hud?

No - at least it didn't yesterday when it still worked for me...

Had the same problem, i fix it by using win 98 compatibility mode. The non GoG Version doesn't have this file. The file comes from the wrapper in the GoG Version.
I played after The Darpa Chief and had no problems so far. Duno if there will be other problems without the wrapper, we will see.

The game works fine for me after following your instructions.

I managed to make MGS 1 work with the Widescreen patch by nemesis2000:

1- Download Nemesis2000's widescreen patch and create a "scripts" folder in the installation directory. Extract "mgs1w.dll" and "mgs1w.ini" to this newly created "scripts" folder and rename "mgs1w.dll" to "mgs1w.asi". The password to extract "mgs.7z" is "mgs".

2- Download ThirteenAG's Ultimate ASI Loader (32-bit) and extract "dinput8.dll" to the installation directory. Then, rename "dinput8.dll" to "dsound.dll".

3- Edit the "mgs1w.ini" file to change the resolution to the smallest possible resolution for the aspect ratio of your monitor, for example, 1280x720 for 16:9 monitors. Then, change the letterboxing option if you want to. Selecting a higher resolution in this .ini file makes cutscenes lag when subtitles are shown. Don't worry, the resolution can be forced through dgVoodoo, which doesn't affect the performance.

4- Delete the existing "mgsvideo.cfg" and "mgsvideo1.cfg" files in the installation directory.

5- Download dgVoodoo. First, install dgVoodoo by extracting it to any folder of your choice. I use "C:\Program Files (x86)\dgVoodoo". Then, copy the "D3DImm.dll" and "DDraw.dll" files located in dgVoodoo's "MS\x86" folder to the game's installation directory ("ddraw.dll" will be replaced). Then, launch "dgVoodooCpl.exe" as admin, click "Add" and select the game's installation directory so a dgVoodoo profile is created for MGS. Select the DirectX tab, force the desired resolution and uncheck "dgVoodoo Watermark". Texture Filtering, MSAA and VSync can also be forced, although MSAA can cause some small graphical glitches and stuttering when launching the game (it lasts for a few seconds).

6- Launch the game and check if a black bar appears in the bottom of the screen. If that's the case, you must rename "dsound.dll" (originally "dinput8.dll") to any of the sugested filenames on the ThirteenAG's Ultimate ASI Loader's download webpage. Don't use any filenames that could replace existing files.

7- When the widescreen patch is working, delete the "dxcfg.exe" and "dxcfg.ini" files from the installation folder, they are useless now.

dgVoodoo fixes all the slowdowns caused in menus, cutscenes with enabled captions and underwater sections. I don't know which dgVoodoo version GOG used, but the REAL dgVoodoo fixes all these issues.

You should end up with these new/modified files in the installation folder
1- "D3DImm.dll" -> dgVoodoo Wrapper (new file).
2- "DDraw.dll" -> dgVoodoo Wrapper (modified file).
3- "dgVoodoo.conf" -> dgVoodoo Wrapper Profile (new file).
4- "dsound.dll" (Or whatever filename is working for you) -> Ultimate ASI Loader (new file).
5- "\scripts\mgs1w.asi" -> ASI Script for widescreen (new file).
6- "\scripts\mgs1w.ini" -> ASI Script for widescreen settings (new file).

You should remove these files in the installation folder:
1- "mgsvideo.cfg" -> Video settings for MGS without widescreen patch.
2- "mgsvideo1.cfg" -> Video settings for MGS with widescreen patch.

I also noticed that the "demo\s0503a1.dmo" file is not the same as the retail version. If anybody knows what they changed, it would be great to know.

Here are two 4K screenshots from the first section of the game:
https://imgur.com/YRGvX0e
https://imgur.com/pVy78W1

Awesome, thank you!

I'm pretty sure it's against the site rules to share sites of Warez sites.

It's not warez, those are just the exes. GOG exes are also cracked, the original game used SafeDisc, which doesn't work on Windows 10.

I tried following your steps but the game opens in a window. Also, where can i find that .sdb file?
BTW, i also noticed that now i can run the game only in software mode.

I thought creating .sdb files was something quite common. Anyway, I edited my post adding a link to download the .sdb files and explaining how to install it. Did you remove "mgsvideo.cfg" and "mgsvideo1.cfg" files?

Oh everything is okay now that i installed the .sdb, thanks a lot for uploading it :D I've seen .sdb files before, but i don't know how to create them.

Btw, a last question. Does the game ask you for the CD? I mean, i know that you can get over that plugging an USB, but it's a bit annoying n___n''

Did you apply the crack and then used upx.bat?