Windows 7 x64 won't be able to get all CPU... it has a maximum of 2 CPU.
2008 Standard edition supports upto 4 multi-core CPU's
2008 Enterprise edition supports upto 8 multi-core CPU's
2008 Datacenter edition supports upto 64 multi-core CPU's
Windows 7 Professional, Enterprise, and Ultimate allow for two physical processors, providing the best performance on these computers. Windows 7 Starter, Home Basic, and Home Premium will recognize only one physical processor.
for sure, these Pu are wuad core? event at 1.6hz, I don't know how much PPD, but you would have 16 cores at 1.6ghz..