Help for 32-bit Operating Systems - Railworks 3

Just stumbled across this earlier and it is worth making people aware of, especially for those struggling to run longer results that occasionally result in an SBHH (Something Bad Has Happened) error. This could be especially relevant for a route such as WCML North. As with any file modifications, take care and backup before making an attempt should you do it wrong.

The following text is taken directly from the original post which can be found here. It is also worth taking a look at the thread itself to see the feedback and results of other users performing this modification, the results seem very impressive for all so far. A big thanks to John (Jarmstro) for researching and making this information available.

I posted this in another thread but I thought it might merit a thread of it own as it will help lots of people with 32 bit OS's. For it to do any good you must have 4GB RAM.


"Those running a 32 bit Operating System with the full 4GB of RAM with at least 500MB VRam and getting freezes, SBHH and ctd's could well benefit from using the so called "3GB Switch". I run Win7 32bit and do not get any problems.

This basically lifts the 2GB program memory limit set by all Win 32bit OS's. The system still can't use more than 4GB but it will stop the OOM errors. The downside is that you really need to make sure you have not got any other other big memory using programs running at the same time as RW3 and its probably better to switch it off when you are not gaming.

At your own risk please but worth a try:


For Windows Vista and Windows 7:
- Create a Restore Point
- Proceed to start -> run and type: cmd (or: You must run CMD as Administrator so alternarively right click the CMD icon etc)
- In opened window type command: bcdedit /set IncreaseUserVa 3072 (You dont need to go the whole hog and could try say 2500)
- Restart PC

For Windows XP:
- Right-click My Computer. Click Properties.
- In the System Properties dialog box, click the Advanced tab.
- On the Advanced tab, under Startup and Recovery, click Settings.
- In the Startup and Recovery dialog box, under System startup, click Edit. The Windows boot.ini file will be opened in Microsoft Notepad.
- Create a backup copy of the boot.ini file. Note: Boot.ini files may vary from computer to computer.
Select the following line in the boot.ini file:

multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Micro soft Windows XP Professional" /fastdetect
Note: Do not overwrite any existing lines.

Press Ctrl+C to copy the line and then press Ctrl+V to paste it immediately below the original line.
Note: Your text string may be different from the text string in this solution, so be sure to copy the text string from your boot.ini file, and not the text string included here.

Modify the copied line to include " /3GB", as shown in the following example:

multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Micro soft Windows XP Professional 3GB" /3GB /fastdetect
Note: Do not overwrite any existing lines.

- Save and close the boot.ini file.
- Click OK to close each dialog box.
- Restart your computer.
- During startup, select the 3GB option. If you do not select the 3GB option, the system will default to the 2GB total memory setting.

Note: If problems occur during startup, you may need to update some of your drivers.

Hope this helps

John A"