High cpu use while computer is idle

I have an older computer (intel E6700;8gb ram, Win7-64). It's usually not doing anything, but it's on and connected to the network. I received a windows message that I was running low on memory and then I noticed that cpu use was 100%. I did a restart and got a prompt that the page file size had been changed. Now, if I run the machine with nothing being done, the cpu use does not go to a low value and line out; it's constantly oscillating between 0 and 10%.

I am seeking help in identifying which processes or services are causing this behavior and/or which hardware, if any may be at fault. I did a full virus scan and there was nothing.

Thanks for any assistance.

Try working thru this:
Troubleshoot Application Conflicts by Performing a Clean Startup

UsernameIssues said:

Try working thru this:
Troubleshoot Application Conflicts by Performing a Clean Startup

I tried that to no effect. Today I noticed that the machine would no longer turn off it's display or put itself to sleep. Now I've done a complete reinstall of Windows 7 and the cpu activity is still there with nothing else installed. I've also tried disconnecting all the peripherals and the network cable and this had no effect. One other thing I tried was a different hard drive running Windows 8; in this case the cpu runs much quieter and not regularly cycling between 0 and 10%. Possibly it's the SSD with the Win 7 on it; it's an OCZ Agility 3?

Try Process Explorer and see if you can determine what EXE/DLL is causing the activity.

UsernameIssues said:

Try Process Explorer and see if you can determine what EXE/DLL is causing the activity.

It's System processes

logicearth said:

Atom said:

UsernameIssues said:

Try Process Explorer and see if you can determine what EXE/DLL is causing the activity.

It's System processes

That would signify it is a driver or hardware issue. Or something that interfaces with the deep levels of the system.

I've updated all the drivers, but it's still there.

Is it due to IO activity?

UsernameIssues said:

Is it due to IO activity?

Nothing on IO. Attached CPU graph with system at idle

Bummer, having a corresponding IO spike would have made things easier to track down.

AVG antivirus used to load their signature files into the System process. This caused a lot of IO traffic to/from that process. Which is why I asked about the IO activity.

Does this CPU activity show up while in the safe mode? (just the safe mode, not safe mode with networking or any of the other safe mode variants)