High CPU usage during idle, but only with log-on screen option enabled

Hello. everyone.
Basically, the fan runs fast if I enable a blank screen saver with log-on screen option.
I having this weird issue and I am at wits' end.

1. My thinkpad will run idle if left alone for a couple of minutes (no noticeable fan sound and Task Manager indicates CPU usage at 1-2%).
No problem here.

2. I can just lock the screen (Win-L) and let it go idling without a problem.

3. If I set the screensaver as "none" and check "on resume, display logon screen" option, it goes to idle without a problem.

4. If I enable the blank screensaver, it will go idle and the monitor will go blank at the specified time (let's say 1 minute).
It will stay as it is.
No problem here either.

5. Now, if I enable the blank screensaver with "on resume, display logon screen" option, it will go idle and the monitor will go blank at the specified time.
However, about 5 minutes later (almost always 5 minutes), the fan starts running at high speed.
It will run noisily until I disrupt the idling by pressing a key or moving the mouse.
This is not an intermittent problem and I can reproduce it every single time.

I tried to see what process causes this high CPU usage with this "#5", but it is not easy to tell because it happens only when I am logged out.
Basically, I leave the Windows Task Manger open and enable the blank screensaver with the logon screen option.
After a minute, the monitor goes blank, and the fan starts running fast after 5 minutes.
Then I disrupt the screensaver by moving the mouse and log-on as quickly as possible to observe the processes on the Task Manager.
But by the time I finishes the logon, all the processes become below 1-2%.
I tried this many times and saw logon.exe on the top of the list a couple of times though.
I guess logon.exe was there because I just logged on, I am not sure.

Is there a program or a way to log process usages?

Thank you for your help.

 

Which ThinkPad and what OS are we discussing here?

 

Hello, ajkula66.

It is shown in my signature.

Thinkpad X201 | Win 7 HP 64bit | WXGA LED | Core i5-560M | 8GB PC3-8500 | 240GB Intel 520 SSD

 

I see now...small print, difficult to read for us aging individuals...

Download Process Explorer and see what it tells you. It gives a much better breakdown of what's going on than the W7 Task Manager in my opinion.

Good luck.

 

Do you know when this problem began? Did you install a Windows update or another program recently? If you have System Restore enabled, I would try taking your computer to an earlier restore point and see if that makes a difference.

 

Hello, Midnight Sun.

I think this problem has existed for sometime (like a year or so).
I have known that sometimes the fan runs faster without a particular legitimate reason.
It's just that I couldn't figure out the pattern until now.