Configuring Windows 2000 to use more than 4Gb of RAM
Windows 2000 Professional and Windows 2000 Server support up to 4Gb of RAM. If you have a machine capable, and have installed Windows 2000 Advanced Server or Windows 2000 Datacentre Server, then maximum supported RAM increases to 8Gb and 32Gb respectively. However, a default installation will only recognise 4Gb.
To recognise more than 4Gb of RAM:
Using Windows Explorer, navigate to the root directory of your boot partition and select boot.ini.
Edit the file properties to unset the Read Only file attribute.
Open boot.ini in a text editor such as Notepad. The file will look something like this:
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows 2000 Advanced Server" /fastdetect
There are two extra switches that can be added to the last line, after /fastdetect: /PAE:Enables support for more than 4Gb of RAM
/NOLOWMEM:Loads the entire system (drivers, pools, programs, etc.) above 4 GB.
Save the changed boot.ini and reset the Read Only file attribute.
Reboot the computer for the changes to take effect.