Instructions for Modifying BOOT.INI To Allow Programs to Access Large Memory
This document describes a method for modification of the Boot.INI file in Windows XP. This applies ONLY to Windows XP and not to other Windows versions. These instructions must be followed VERY CAREFULLY. Failure to do so may cause your system to become unbootable.
Step 1 -- Back up your system
Please begin by making a full backup of your computer. This step is not required if you are setting up a fresh XP Mode environment under Windows 7
Step 2 -- Become familiar with the Windows XP Recovery Console
Before making this change to your Windows XP configuration, be sure you are familiar with running the Windows XP Recovery Console. Anytime you make changes to the configuration of your computer, there is a possibility of making a mistake that could cause problems booting your computer. The Windows Recovery Console can be used to repair these mistakes. We recommend you practice using the Windows Recovery Console before beginning this procedure.
For more information about the Windows Recovery Console, refer to:
Using Recovery Console, Microsoft TechNet.
Recovery Console, The Elder Geek.
Windows 2000 / XP Recovery Console, World of Windows Networking.
Step 3 – If needed, Apply XP Service Pack 3, and all relevant and current security patches. Again, the Windows 7 XP Mode environment should already be up-to-date.
Step 4 -- Edit boot.ini to enable 3 GB addressing
Boot.INI it can be accessed through the System control panel.
Open Control Panel, then open the System panel.
On the "Advanced" Tab, click the "Settings" button in "Startup And Recovery". You should see the following panel:
To edit BOOT.INI manually, click the "Edit" button in "System startup", which will bring up Notepad with BOOT.INI in it. Add /3GB to the options on the command line which refers to Windows XP Professional. Be sure to include a space before the / character when you add this to the end of the existing line. On most systems this will appear similar to the following:
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /3GB
DO NOT MAKE ANY OTHER CHANGES IN THE BOOT.INI FILE, OR YOUR SYSTEM MAY BECOME UNBOOTABLE.
Save the file, then close all windows.
Step 5 -- Increase the size of your paging file
You should also increase the size of your paging file to at least 4096 MB (4 GB). It is necessary to increase the size of the your paging file beyond 3 GB because it is shared by all processes on your computer.
Use this method to set the swap file size:
1. Go the the Control Panel (from Windows Start menu).
2. Double-click the System item.
3. Select the Advanced tab on the System Properties dialog.
4. Click the Performance button.
5. Click the Change button on the Performance Options dialog.
6. Enter the value “4096” into both the Minimum Size and the Maximum Size text field and then press the “Set” button, followed by OK on all the dialogs:
Make sure that the Paging File Size in the white box above reads “4096 – 4096” before clicking OK.
Step 6 – Reboot the computer
Now reboot the computer. This should activate the “Large Address” feature in Windows XP.
Please double-check your changes to boot.ini before restarting your computer!
Step 7 – Be sure that you are using the latest version of FLOWCast
Go to the Download page of the website and download the latest SOLIDCast Update file. This contains the latest version of FLOWCast which has the 3GB option.
Note: We recommend that your computer have 4GB of RAM total if you are going to be running large FLOWCast simulations using this option.