I see a lot of people complaining about no Widescreen for Dawn or War. Let me help with that as I made mine widescreen.

It is not as easy as dropping in a file, but it certainly can be done:

Modifiying the Files yourself

First you will need a Hex editor and a Text-Editor you can download the Hex editor from:
http://mh-nexus.de/en/downloads.php?product=HxD
I recommend Notepad++ for Text editing or use the default Notepad:
http://www.notepad-plus-plus.org/

Go to your installation folder and open the file "Local.ini" with a Text-Editor and change your "screenheight" and "screenwidth" to your desired Resolution:

1920x1080:
screenheight=1080
and
screenwidth=1920

1366x768:
(It needs to be 1360x768 in the ini)
screenheight=768
and
screenwidth=1360

1680x1050:
screenheight=1050
and
screenwidth=1680

(Don't change the Resolution in the Options otherwise it will reset the Local.ini and you have to edit it again)

Now you need to search and edit the hex values in all five .exe files, open them with HxD and search with (ctrl+f) for ABAAAA3F don't forget to change the Datatype from Text-string to Hex-values:

Open "W40k.exe" with the Hex editor and search (ctrl+f) for the hex value ABAAAA3F. When you have a 16/9 monitor Replace it with 398EE33F for 16/10 change it to CCCCCD3F Save your file.

Open "W40kWA.exe" with the Hex editor and search (ctrl+f) for the hex value ABAAAA3F. When you have a 16/9 monitor Replace it with 398EE33F for 16/10 change it to CCCCCD3F Save your file.

Now open "Platform.dll" with the Hex editor and search (ctrl+f) for the hex value ABAAAA3F. When you have a 16/9 monitor Replace it with 398EE33F for 16/10 change it to CCCCCD3F Save your file.

Now open "spDx9.dll" with the Hex editor and search (ctrl+f) the hex value ABAAAA3F. When you have a 16/9 monitor Replace it with 398EE33F for 16/10 change it to CCCCCD3F Save your file.

Now open "UserInterface.dll" file and search (ctrl+f) for the hex value ABAAAA3F.
You should find 2 occurrences of this value in this file. Replace both values with 398EE33F if you have a 16/9 monitor or CCCCCD3F if you have a 16/10 monitor. Save your file and close your hex editor.

A guide on how to mod your Dawn of War to run on modern resolutions and aspect ratios.
VVV--- USEFUL STUFF BELOW ---VVV

This tutorial should work for Dawn of War, Dawn of War: Winter Assault, Dawn of War: Dark Crusade and Dawn of War: Soulstorm.

[16:9 HEX VALUES]
W40K.exe = 39 8E E3 3F
Platform.dll = 39 8E E3 3F
spDx9.dll = 39 8E E3 3F
UserInterface.dll = 39 8E E3 3F

[16:10 HEX VALUES]
W40K.exe = CC CC CD 3F
Platform.dll = CC CC CD 3F
spDx9.dll = CC CC CD 3F
UserInterface.dll = CC CC CD 3F

[21:9 HEX VALUES]
W40K.exe = AB AA AA 3F
Platform.dll = 26 B4 17 40
spDx9.dll = 26 B4 17 40
UserInterface.dll =26 B4 17 40

[CAMERA/ZOOM FIX MOD]
https://www.moddb.com/games/dawn-of-w...

Any issues please feel free to comment and I'll do my best to help.

[SOURCES]
"Yorith" Steam Guide: https://steamcommunity.com/sharedfile...
"Ghazzgul" Steam Guide: https://steamcommunity.com/sharedfile...

Aspect Ratios

To calculate your aspect ratio decimal, divide the resolution's width by its height. Note that ultra-widescreen is marketed as 21:9 but the aspect ratio actually varies slightly between resolutions (these are listed separately below).
Common Name Decimal Formatted Value
5:4 1.25 00 00 A0 3F
4:3 1.33 AB AA AA 3F
3:2 1.5 00 00 C0 3F
16:10 1.6 CD CC CC 3F
15:9 ~1.66 55 55 D5 3F
16:9 ~1.77 39 8E E3 3F
1.85:1 1.85 CD CC EC 3F
21:9 (2560x1080) ~2.37 26 B4 17 40
21:9 (3440x1440) ~2.38 8E E3 18 40
2.39:1 2.39 C3 F5 18 40
21:9 (3840x1600) 2.4 9A 99 19 40
2.76:1 2.76 D7 A3 30 40
32:10 3.2 CD CC 4C 40
32:9 ~3.55 39 8E 63 40
3x5:4 3.75 00 00 70 40
3x4:3 4 00 00 80 40
3x16:10 4.8 9A 99 99 40
3x15:9 5 00 00 A0 40
3x16:9 ~5.33 AB AA AA 40