Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Which PCI-Express has a DDR 266/333/400 Registered/ECC memory and Enhanced AC'97 2.3 sound?

### Inputs:
table_name: table, columns: ['Model', 'Processors Supported', 'FSB/HT Frequency (MHz)', 'Memory', 'PCI-Express', 'SATA', 'PATA', 'Sound', 'Network', 'Features']

### Response:
SELECT PCI-Express FROM table WHERE Memory = ddr 266/333/400 registered/ecc AND Sound = enhanced ac'97 2.3