user: ### NOW ANSWER:
Question: Which PCI-Express has a DDR 266/333/400 Registered/ECC memory and Enhanced AC'97 2.3 sound?
Columns: ['Model', 'Processors Supported', 'FSB/HT Frequency (MHz)', 'Memory', 'PCI-Express', 'SATA', 'PATA', 'Sound', 'Network', 'Features']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'real', 'text', 'text', 'text']
Sample row: ['nForce3 Professional 150/250', 'AMD Opteron', 'HT 1.0 1.6 GHz', 'DDR 266/333/400 Registered/ECC', 'N/A', 4.0, 4.0, "Enhanced AC'97 2.1", 'GbE: 1 connections', 'MediaShield']
SQL:

assistant: SELECT "PCI-Express" FROM "Table" WHERE "Memory" = 'DDR 266/333/400 Registered/ECC' AND "Sound" = 'Enhanced AC''97 2.3';