CREATE TABLE table_38740 ("Model" TEXT, "Processors Supported" TEXT, "FSB/HT Frequency  ( MHz ) " TEXT, "Memory" TEXT, "PCI-Express" TEXT, "SATA" FLOAT, "PATA" FLOAT, "Sound" TEXT, "Network" TEXT, "Features" TEXT)

Which PCI-Express has a DDR 266/333/400 Registered/ECC memory and Enhanced AC'97 2.3 sound?
SELECT "PCI-Express" FROM table_38740 WHERE "Memory" = 'ddr 266/333/400 registered/ecc' AND "Sound" = 'enhanced ac''97 2.3'
SELECT "PCI-Express" FROM "table_38740" WHERE "Memory" = 'ddr 266/333/400 registered/ecc' AND "Sound" = 'enhanced ac\'97 2.3'