If you used an unattended installation, or floppy disks, to install Windows NT 4.0 Enterprise Edition on a computer with more than 256 MB of RAM, you better check the Boot.ini file for the /maxmem=256 switch.
During installation, the /maxmem=256 switch is added to the Boot.ini file to prevent possible problems when the NT code base is installed on a computer with more than 256 MB of RAM.
NOTE: When you install from a CD-ROM, the switch is automatically removed at the completion of the setup process.
To resolve the problem:
1. Open a CMD prompt.
2. Type attrib -r -s -h c:\boot.ini and press Enter.
3. Open the c:\boot.ini file in Notepad.
4. Remove the /maxmen=256 switch.
5. Save the c:\boot.ini file.
6. Type attrib +r +s +h c:\boot.ini and press Enter.
7. Shutdown and restart Windows NT 4.0 Enterprise Edition.