With standard Windows NT Server, the per-process address limit is 2 gigabytes (GB) of random access memory (RAM). The 4GT feature of Windows NT Server/E increases this limit to 3 GB without introducing new APIs. 4GT does this by reducing the potential RAM allocated to the Windows NT kernel from 2 GB to 1 GB.

Change the attributes for BOOT.INI so it is not 'Read Only', BOOT.INI is found in the root directory of the first partition. And open the file using Notepad or another text editor (not Microsoft Word or any word processor).

Listed under the [operating systems] section are all the OS's the NT boot loader can launch.

At the end of the each entry add '/3GB' (without the quotation marks).

The new entry should look similar to:
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Server Version 4.00" /3GB

Restart Windows for the change to take effect.

Note: This change is only effective if you are using Windows NT Server/E. On standard Windows NT, this flag will relocate the kernel, but applications will be unable to access more than 2 GB.

Disclaimer: Modifying the registry can cause serious problems that may require you to reinstall your operating system. We cannot guarantee that problems resulting from modifications to the registry can be solved. Use the information provided at your own risk.