Why is my PC's CPU always running at 100?

Why is my CPU running at 100%?

• My CPU has been running at 100% for a while now. I thought it might be a virus that I could not get rid of or a hard drive problem, so I bought a new hard drive, installed it, and installed Vista on it. Since I put in the new hard drive, I have not connected it to the internet or downloaded anything so I don't believe I have a virus or malware, yet the CPU is still running at 100%. When I open my resource manager, the primary culprit seems to be a system process called "NT Kernel & System which is using over 90% of my processor. Any Ideas what might be the problem?

• Answer:

  You probably have some bad hardware that is generating constant device interrupts. These are the highest priority for the operating system, so it will spend as much time as it has servicing them. I can't tell from your problem description what it might be, but some common devices are network cards (#1), graphics cards (#2), drive controllers (#3), audio cards (#4), & then everything else (modem cards, etc.). The only way to diagnose this is to remove all unnecessary cards & see if the problem persists. Add them back in one at a time until the problem reoccurs & the last card added is the culprit. You'll need to replace it.