Try use Dos32a. It is a replacement for DOS/4GW and fixes a lot of memory issues. For instance when I played Syndicate Wars and blew stuff up, sometimes all the colors got corrupted for lack of better word. Dos32a fixed that issue.
You can get the Dos32a
here. If the page doesn't work try google it
There are 3 ways to use it and I quote:
There are several ways DOS/32 Advanced can be "plugged" into your 16-bit and 32-bit protected mode applications and games. The simpliest way to replace the old DOS/4GW DOS Extender provided with many programs is to copy DOS/32 Advanced executable file dos32a.exe into the directory where you installed the software (the directory containing dos4gw.exe file), delete the old dos4gw.exe file and rename dos32a.exe to dos4gw.exe. You can always preserve the old dos4gw.exe file by copying it into another directory, and if the program you intended to run with DOS/32 Advanced is not 100 per cent DOS/32 Advanced compatible, you can always recopy the old dos4gw.exe DOS Extender back.
Below are listed three different examples which show three different ways of how you can use DOS/32 Advanced DOS Extender in your programs. Please note that the examples assume you are using an MS-DOS or compatible Operating System.
Example 1:
You have installed the game TIE FIGHTER (CD Version) into directory C:\GAMES\TIECD. In the same directory is located file dos4gw.exe.
STEP 1) Copy file dos32a.exe into the directory C:\GAMES\TIECD, type at DOS prompt:
copy dos32a.exe C:\GAMES\TIECD
STEP 2) Preserve file dos4gw.exe in C:\TEMP directory and remove it from C:\GAMES\TIECD, type at DOS prompt:
cd C:\GAMES\TIECD
move dos4gw.exe C:\TEMP
STEP 3) Rename dos32a.exe to dos4gw.exe, type at DOS prompt:
ren dos32a.exe dos4gw.exe
STEP 4) Start the game as usual by typing tie at DOS prompt.
Note that if you do not want to preserve the old file dos4gw.exe you can simply type at DOS prompt:
copy dos32a.exe C:\GAMES\TIECD\dos4gw.exe
Another way to use DOS/32 Advanced with your protected mode applications is to execute it on a program by typing at DOS prompt: dos32a myprog.exe where myprog.exe is the file that is to be run. This way, you can keep the files unmodified on your hard drive but run them under DOS/32 Advanced, or start programs from CD-ROMs where the files can not be modified. You can also create batch files in which you can place the commands described below to simplify the start of your programs. Please note that DOS/32 Advanced DOS Extender is capable of starting programs from the command line even if they are bound to another DOS Extender, for example DOS/4GW Professional!
Example 2:
You have installed the game DOOM II into directory C:\DOOM2. In the same directory is located file doom2.exe which is the game's executable file.
STEP 1) Copy the file dos32a.exe into the directory C:\DOOM2, type at DOS prompt:
copy dos32a.exe C:\DOOM2
STEP 2) Create a batch file d2.bat, type at DOS prompt:
cd C:\DOOM2
copy con d2.bat
@dos32a doom2.exe
^Z
File d2.bat will be created after you press ^Z (CTRL-Z) key combination to interrupt the input. Start the game by typing d2 at DOS prompt.
The third way to use DOS/32 Advanced with your protected mode applications is to bind it to a program. You must use the SUNSYS Bind Utility program sb.exe which is included with DOS/32 Advanced DOS Extender. When binding DOS/32 Advanced to an executable file, the old DOS Extender or stub file which was bound to the application will be removed and discarded. Therefore you should make sure that the program is DOS/32 Advanced compatible. This can be done by executing DOS/32 Advanced on program's executable file as described above. The following example will show how to bind DOS/32 Advanced to a program:
Example 3:
You have installed the game DUKE NUKEM 3D into directory C:\DUKE3D. In the same directory is located file duke3d.exe which is the game's executable file.
STEP 1) Use SUNSYS Bind Utility to bind DOS/32 Advanced executable file dos32a.exe to a program, type at DOS prompt:
cd C:\DUKE3D
sb -r duke3d.exe
The Bind Utility will report its actions and show the final size of the file duke3d.exe. You will notice that it had changed and became smaller by almost 200KB. The game can now be started as usual.
Sorry for the long quote but I am so tired of people linking to a fix and then 2 years later neither the guy who posted it nor the webpage is around any longer.
I believe you have to use example 2 or 3 with shadow warrior since it lacks the DOS/4GW.exe.