The widescreen fix can now be found here.

Thank you. This patch deserve a more permanent place like moddb.

There's also a copy on the PCGamingWiki here.

The more, the merrier. Didn't know that site.

Just a quick note: version 1.05 of nGlide is going to add support for custom resolutions. I have implemented the required driver changes and I will publish a new version of this fix that incorporates the patched Glide driver once 1.05 is released.

As nGlide 1.05 has now been released, here is the new version of the widescreen patch:
Undying Widescreen Fix 1.01
The only change in this version is the addition of the patched Glide driver.

Link updated on 2017-03-26.

Thank you very much drennan! :)

As I've mentioned on the official nglide forums: The patch is working perfectly and your work is much appreciated!

Hi, I just bought and did a fresh install of Undying on my Windows 7 with Geforce 770 desktop PC. I installed nGlide 1.05 (which works great for other games I tried), but it will not let me use widescreen or even change the resolution of this game. I used the updated patch 1.1 that was linked to here (put both files in the subfolder mentioned), but it will not let me change the resolution on the main video screen. The screen will go black for a second and then back to the original lowest resolution as well as back to 16 bit. If I go to direct X, it works fine.

I want to run the game at 1920x1080. Any ideas?

Renamed glide2x.dll file in System folder?

Great! Thanks. I did not see that in the directions, but once I deleted that file, I was able to get it working.

do this, hope it'll help you.
But you need to copy only 4 files:
glide.dll
glide2x.dll
glide3x.dll
nglide_config.exe

You can grab the nGlide installer form here:
http://www.zeus-software.com/downloads/nglide

And the Undying Widescreen Fix from here

Good luck!

That did the trick!
Thanks a lot mobutu.

You're welcome, enjoy the game! I know I just started it (for the first time), but so far I'm really liking the atmosphere, story and plot, It's a very promising game! Hope it'll keep this way until the end ;)