CPU-z works just fine on my Vista machines. If Control Panel is reporting incorrect information about your CPU, it sounds like your motherboard BIOS does not recognize the processor properly. Check for a BIOS update that includes support for the CPU that you have installed.
"I did RC5, but I didn't flush." - Bill Clinton
"I invented distributed computing." - Al Gore
"I had a dream where every American would be free to run SETI@Home!" - Martin Luther King Jr.
"Greendale is a bodaciously small town, Lane... I can't even Find-A-Drug here!" - Charles De Mar (Better Off Dead)
"I did not have BOINC relations with that woman, Rosetta@Home!" - Bill Clinton