Yes, CPU-Z should show 4 cores and 8 threads, as everything else you listed should. It sounds like you may be experiencing "core parking", a Windows power management thing. How that became enabled in the first place is weird, I have never experienced it myself so I don't know much about it. I suggest searching on "core parking", although what I found was not the greatest IMO. Here's one link that might help you:
The following is not a fix, but a nice hardware monitor that will show the usage of the four real cores in bar graph form in real time, HWiNFO32, available free here:
The only other thing I can think of is a BIOS setting for "legacy" OS's being enabled, but that is a stretch. Did you try flashing your BIOS to the same or newer version, maybe it became corrupted?
Let us know if you figure this out. I have never heard of a CPU having this problem, but who knows? I have an i7-930 and have never experienced this.
I followed the advice of a guy that responded toa similar post to someone who had the same problem but in Vista, by going into MSCONFIG, boot and advanced options however my option said 1 processor not 1 core and 1 processor is correct but I deleted it left it blank and rebooted. When windows opened up I checked cpuz and core temp and both report 4 cores a nd 8 threads the way it should be. So i tip my hat and say thank you to Laptopluey8. I suggest you try his method because it worked for me.
here's the link to the post I refered to http://communities.intel.com/message/126647#126647
I do thank you also for taking the time tio try and help me, I just read his response firs and tried it and success, so I'm happy. Thanks again
Sounds good Dan, whatever works! I did figure out the command lines from that article, which has typos in the commmands, OMG, given how messy they are, they ought to be right in the first place. I ran them and now I can tweak my core parking... Oh Joy!! I might try it for a test but I don't want to end up how you were. Sure, I bought a four core/eight thread CPU so I can turn some of them off... Ok, so it's supposed to be temporary, but can I trust that?
I still wonder how you ended up with an i7-mono-core CPU. I would have liked to see what your PC had the core parking max and min cores set to. Then again, maybe that is unrelated to the MSCONFIG fix you did. Some of the new Intel Server CPUs have 10 cores, 20 threads, maybe that on can actually use that feature.