View Full Version : High CPU usage when network cable's in

06-16-2011, 05:20 AM
I have a problem with my Windows XP desktop PC..

* I was browsing internet as normal, when I wanted to watch a YouTube video. It started to play but then the PC froze. I couldn't do Ctrl+Alt+Del or move mouse and so. Suddenly the screen went all in rainbow colored stripes, something like the 'snow' when TV cannot find a channel.
* I pressed the 'Restart' button on the case of my PC, as the normal 'Power' button did NOT work due to the PC freeze
* The normal screen with all the 'Press F2 to enter Setup' 'Press F11 to enter Boot menu' texts appeared, but it didn't go away in a few seconds, like it always did. Instead, it showed the Boot texts (I think), with the first Boot device. Then the computer froze. I pressed 'Restart' again.
* After a few tries, the PC got pass the Boot texts, but now showed 'Insert Boot driver and boot the system again' (or something like that). I didn't understand what the PC wanted me to do, so I pressed 'Enter' key, but it just repeated the line. Again - 'Restart'.
* Again after a few tries, the PC managed to boot up to the desktop screen. It showed 'Active Screen Recovery'. I ignored it. Then I opened Task Manager, just to see that the CPU usage jumps from 50% to 100%. Computer froze.
* I started it up again, when after a few unsuccessful tries to get pass the boot texts, I managed to get to the desktop screen again. I decided to Defragment the system. It defragmeneted till 19% when it stopped there for 20 minutes, so I just stopped the defragment process completely. The Task Manager still showed high CPU usage. I did Disk CleanUp, but nothing changed. PC froze...
* At the next try, I started my AVG AntiVirus, and - voila - 16 Trojans! I was actually happy to see them, because I thought that I found the source of the problem, and indeed - CPU usage dropped to normal 0 - 30%.
* After few days, my PC froze again. I was mad at it, because it was running smooth after the antivirus scan, but the CPU Usage again jumped from 50 - 100% (many times even stayed at the very top of 90 -100%). So, know when I knew what I had to do, I started AVG Antivirus scan. But after scanning 800,000 files, the PC froze without showing up any viruses (only some 'files with broken digital signatures').
* I had read somewhere, that with sytem problems, there is an option to restore the system. I did everything as said in tutorial, but the Windows showed that the System Restore was UNsuccessful. Tried to restore it to more system checkpoints, but again with no results.
* Booted the PC after few tries of the problems mentioned in the second and third paragraph. I tried to clean up the C drive, as my PC has integrated CPU on motherboard. I deleted a few big files and clean the drive till about 50% was free. But some 30GBs were still hiding somewhere, so I checked the folders in the C:. And what you know - a 26GB folder (18GB size on disk) with the left overs of the compressed hard drive files when this PC was taken to service because of some problems. I tried to open this folder to see what's in it, but, as you may already guess - the PC froze again.
* Willing to try again, as some clues of my problem were showing up, I rebooted PC. Without any problems (just slower booting) I came to the 26GB folder. I inserted my USB Hard Drive into the USB port, and started to copy the big folder from the PC to the USB HDD. After 2 hours or so, it was done. I was wondering why the PC hadn't frozen before a long time. Luckily, I accidentally noticed that the network cable had been unplugged (because I share the cable between my PC and the WiFi router for mobile devices). Out of interest, I checked the Task Manager and found out that the CPU usage had dropped to 0 -10% when not doing anything on the PC. Now that I knew what probably was the cause of my problem, I did an experiment.
* I powered off my PC normally (hadn't been done for a long time due to the problems). Then I put the network cable in the port, and booted my PC. When it get to the desktop screen, I checked the Task Manager, and indeed - CPU Usage 50%-100%. Unplugged the cable, dropped to 0-20%.
* So, I checked the glory internet (from another PC) and tried to Google my problem. I found a site where a guy with a bit similar problem had written a question on some forums. A helper said to him, to try and stop the un-needed StartUp processes, with a link to a useful site where I can see if a StartUp process is needed, un-needed or even a virus. So, I made a list of my PC's StartUp processes, and headed to the PC with internet and checked all the processes. Turned out I could cut half of my processes. So, I got back to the problematic PC and unchecked all the un-needed StartUp processes from MSCONFIG. Then I rebooted the PC with networ cable IN. But, unfortunately, the CPU was still very high (even got stuck at 100% for some time) and then the PC froze.
* It was the last time I booted my PC. It happened looong looong time ago, yesterday, I think. Haven't turned it on since, because I cannot guarantee that I won't throw the PC out my window (ironic, huh, Windows out of window)

Now, that I have told you my short story, I am asking you, dear computer-knowing-people: what is the solution to my problem?

You are the last resort, till I take the PC to service.

Thank you!

06-21-2011, 04:24 PM
My solution is that I would have formatted the PC the first time I seen Trojans.....................AVG might not have got everything and 16 trojans can't be good................
Can you do this yourself? or are you going to take it in to have them do it for you? Cost you about $50 normally but some soak ya for this service....check first on the cost for a straight format (don't even save you stuff on the HDD cause it might just pass on an infection to the new setup)

Hope you had a good back-up pluging the PC into a router should not have done this, but to be sure, unplug the router from power for 2 minutes and plug it back in..................I have had trouble with wireless routers needing reseting from time to time

06-21-2011, 04:32 PM
The solution to your problem is you are still probably infected. Follow the instructions here (http://www.pcguide.com/vb/showthread.php?t=60009) and post a Hijackthis log for review.