I configured both an E521 and a E521n identically

PROCESSOR AMD Athlon(TM) 64 X2 Dual-Core 3800+
OPERATING SYSTEM FreeDOS(TM) included in the box, ready to install
MEMORY 1GB Dual Channel DDR2 SDRAM at 533MHz- 2DIMMs
HARD DRIVE 320GB Serial ATA Hard Drive (7200RPM) w/DataBurst Cache(TM)
OPTICAL DRIVE 16x DVD+/-RW Drive
MONITORS 19 inch E197FP Analog Flat Panel
VIDEO CARD 256MB NVIDIA Geforce 7300LE TurboCache
SOUND CARD Integrated 7.1 Channel Audio
My Accessories
SPEAKERS No speakers (Speakers are required to hear audio from your system)
KEYBOARD & MOUSE Dell USB Keyboard and Dell 2-button Scroll Mouse
FLOPPY & MEDIA READER No Floppy Drive Included
MODEM 56K PCI Data Fax Modem
My Software
My Service
WARRANTY AND SERVICE 1Yr Ltd Warranty and At-Home Service

The one with Free DOS (no OS) final cost is $789

The one with WinXP Media Center Edition 2005 is $769

The 320GB hard drive is a free upgrade for the Windows system, but for the non-OS system it adds to the cost. What a crock.