Windows 7 forum: 100% CPU Usage After Unplugging AC Power

I do agree that it is a Microsoft problem, but NOT a Hewlett-Packard problem. I have a Dell Inspiron 1545 running Windows Vista Home Premium (32-Bit) and I have the same problem. I have nothing installed other than what the factory pre-loaded, along with Microsoft Office 2007. I am a webmaster for an United States Air Force Auxiliary Squadron, and it is very difficult to manage such, along with school and my job, when my computer won't do anything when on battery. I have found that even if I plug the computer back in, I have to reboot it to get it running to normal standards. Any help would be appreciated, as long as it is relevant to the current thread's situation.

Thank you.

Well i guess the person who said about reproducing the problem with skype applies to me as well.

But i can even say that i made a clean install and nothing else and try to open IE or just try to do some activity and after 1-2 mins the task manger will show cpu of 100%.

the other way i can reproduce this problem is connect the laptop to tv and start a movie and then disconnet the power you will instantly see the effect.

Weill i understand what you say .but i dont think you understand what the actual problem.
Dont think that i dont know about the working of computers .
I have got lots of experince in it.

Can you be able to explain why the same issue does not come in safe mode in battery .

the problems i am refereing to is that when you are watching a movie connected to the TV and removed the power OR just browsing web OR using skype and remove the ac power the cpu REMAINS at 100% and the computer is not responsible.

I have even seen the issuse to come just after a restart and removing the ac power.

NOTE : THIS MIGHT NOT BE IN YOUR CASE...YOU NEED TO SEE THIS ...


I am not taking about the spikes inthe CP graph i understand they can come .but staying at 100% ???

Of course I've installed software. I'm not going to wait around on Mircosoft or HP to fix this problem with a bare install sitting on my computer. Not installing other software is like having a new car, but not having anywhere to drive.
But the fact that this problem occurs in other programs seems to point to the OS/drivers rather than Skype itself.

Well i tried a different approach and seems to be working now.
Go to power options and change the processor cooling policy to Active (if it is passive) in both balanced and in power saving mode and in both On battery and Plugged in options in windows 7.

Now i can unplug the AC power and the laptop is running normally even if i unplug the AC power.

I can trace this problem to processor - Fan - Optical Drive.But not exactly to one.

I see this problem to be only on this HP HDX 16t models with windows 7
and even strange it happens in only few systems.

I hope this fix will solve your problem .If you need more info PM me.

This worked for me as well.

Same boat as the other posters. HP Pavilion dv7, 100% CPU when the AC is unplugged. Your fix provided instant relief!

Ironically, I was on a live chat with HP customer service, getting nowhere with them, when I stumbled upon your solution. It seems incredible to me that this problem could have been reported by so many people, but HP was completely oblivious to it.

Anyway, thanks again!

I am glad to see that people are able to fix the same issue i had .

i wish if there is any possible way to mark the question marked as solved or has fix because most of the people who have the same issue might come across this thread and go away without seeing the entire thread .If they do see the question marked as solved or has a fix it might help them.

I also wish if this message could be passed on to the makers of the laptop so that they can come out with a permanent solution.

I had the same problem, and sashank_1234's solution seems to have cured it!

my system: HP HDX 18T
Intel Core2 Duo T9900 @ 3.06GHz 3.07GHz
3GB RAM, 64bit OS
Windows 7 Ultimate (upgrade from new Vista install)

The problem would happen at random times to random programs, but usually when I was trying to multitask, most often when I was watching a video, and EVERY TIME when the power had gone off. (It does that a lot here.)
I have no idea what the CPU usage was, but my computer would slow down to a snail-caught-in-molasses pace. That drowning robot is what my movie sounded like. I hit CTRL-ALT-DEL, and had time to grow a beard and braid it by the time Task Manager showed up.
Reinstall Windows? Yeah, I have time for that. Update my drivers? HP keeps interrupting me to tell me they're fine!! THANK YOU, sashank for the reasonable solution that worked! The problem was the difference in the processor cooling policy between power & battery - going from Active to Passive.

Sno