Strange behavior after PC is left on overnight

[Quattro Pete]

This is a Dell Vostro200 running Vista SP1.

If I leave the computer on overnight, some strange things happens in the middle of the night. Around 4-5 am every night, the monitor comes on (it is normally set to turn off after an hour of inactivity), and I hear my external USB drive running for a few seconds. The screen appears asking me what I want to do with that drive (the typical screen that comes up whenever you plug in a new USB drive). So, it looks like that drive just got disconnected and then reconnected right back.

One other symptom: a System process called "NT Kernel" (or something like that) starts chewing up betw. 30% to 50% of my CPU resources. I have to reboot the PC if I want this high utilization to go away.

I tried to look at the system scheduler to see if there were any tasks scheduled that would coincide with that timing, but I haven't been able to find anything. Maybe I'm not looking in the right place. What should I be looking for and where?

I run Avira antivirus, Spybot S&D, CCleaner... the usual stuff. None of it finds anything unusual.

 

[GrtArtiste]

Maybe this would be helpful to get a better look at your system. If you spot an unfamiliar program running, you can google and find out what it is.

http://www.whatsrunning.net/whatsrunning/main.aspx

GrtArtiste

 

[Quattro Pete]

Does it run under Vista? It's not mentioned on that site.

Anyway, I don't think that's what I need. I already know which specific process it is. What I need to know is why it's doing it. Normally, that process (NT Kernel & System) takes up 0% CPU, but in the middle of the night, it goes to 50% and doesn't let go.

 

[ToyotaNSaturn]

Things that run by themselves in Vista that cause the most angst: Windows Defender, the built-in Search service.

Any of these things can be scheduled to wake up the machine. Check through these components to see if they are set to do just that. Perhaps just disabling them for a night or two?

 

[Quattro Pete]

Originally Posted By: ToyotaNSaturn
Things that run by themselves in Vista that cause the most angst: Windows Defender, the built-in Search service.

Thanks, but that does not explain why the external USB drive seems to get disconnected and reconnected.

Also, the machine doesn't really wake up since it never actually goes to sleep/standby. Only the monitor gets turned off and then comes on at night.

 

[GrtArtiste]

Originally Posted By: Quattro Pete
Does it run under Vista? It's not mentioned on that site.



I run it under both XP and Vista. No troubles so far.

 

[Steve S]

I have an POS Acer with vista that turns itself on. I turn the power off on the surge protector. Big brother type vibes.

 

[MONKEYMAN]

Are you still under warranty? What does Dell have to say? If out of warranty I found the Dell Forum a good place to get info on problems with a particular model:

http://www.dellcommunity.com/supportforums/?~ck=ln&lnki=0&nav=true

 

[greenaccord02]

If there is a virus scan/defender scan that happens at night, that process could be unmounting the drive to scan it. Then when the process finishes it attempts to remount the drive, thus the 'new' device prompt. Vista likely wakes up the monitor to show you the prompt.

 

[Quattro Pete]

Thanks. That would make sense, except that Windows Defender is switched off and I don't have any virus scans scheduled.

However, I just realized my power settings weren't what I thought they were. I noticed that I had the settings modified to put the computer into Sleep mode after 5 hours. So, what I probably seeing at the wee hours is the computer coming out of the Sleep mode, and hence the USB drive message popping up on the screen and the monitor coming on.

I've read other people observed various issues (such as increased CPU usage) after bringing the computer out of Sleep mode.

I'm wondering what brings my PC out of the sleep mode though? Wake-on-LAN I suppose?

 

[Quattro Pete]

A bit of an update on this: I realized it is my Logitech wireless mouse (MX Revolution) that is somehow responsible for this high CPU usage after coming out of the standby/sleep mode. If I keep the mouse's wireless adapter disconnected from the USB port, then the problem disappears.

I contacted Logitech support and will see if they have any solutions. I couldn't find a driver on their site, so I am just using the OEM Microsoft driver with this mouse.

 

[NJC]

Originally Posted By: Steve S
I have an POS Acer with vista that turns itself on.

It might be a setting in BIOS to automatically turn on. Worth a check.