The widescreen fix for Warrior Within doesn't work. After editing the ini file (to 1920x1080) and running upx, the game still does not display nor allow changing to the new resolution. Running upx just causes a window to flash up for half a second before disappearing anyway, with no hint that it actually did anything.

What do I do to get this to work?

Running into the same issue as dmr: I need 1920x1200 but the Two Thrones only provides 16:9 resolutions natively. Using the patch, even after unpacking pop3.exe with upx, does not change anything while it worked like a charm on the two previous games. Could you describe again what you did? I unpacked the two dlls and the ini in the installation directory, unpacked pop3.exe using upx (now it weights 6MB), edited the desired resolution in pop3.ini.

darkredshift : the patch I used for Warrior Within was different, it is called universal widescreen patcher with a graphical interface that does everything automatically. Well, almost automatically, you need to unpack pop2.exe with upx beforehand so the patch can recognize the executable.
upx.exe is a command line program, the upx.bat makes use of upx.exe to unpack pop2.exe, are you sure you launched this bat file instead of upx.exe? Anyway, since it is command line program, the flashing window is expected: it actually prints some text and exits straightaway. Just check that pop2.exe is bigger after you've launched upx.bat.

Got it to work with a cracked exe just search for it, its easy, then with the universal widescreen patcher as admin, and voilá!!!