High CPU idle when Ethernet cable plugged in

I recently noticed that my CPU idle is quite high and is consistently between
20-30% even when I am not using the computer even after a fresh restart. I
have found that it is the System process (not the System Idle proces) which
is hogging 20-29% of my CPU.

First my computer's relevant specs:

Acer Ferrari 4000 Notebook
----------------------------------------------------
AMD Turion 64 Mobile 2.0 GHz Processor
1 GB RAM
Windows Vista Buisiness RTM
Broadcom NetLink Gigabit Ethernet 10/100/1000


I used msconfig to disable all startup programs and non-Microsoft services.
Upon restart this is what my CPU usage looked like after letting the computer
sit for 5 minutes without touching it:

http://img226.imageshack.us/my.php?i...uggedinuz9.jpg

Notice that the CPU spikes up to about 27% from about 5% and the average CPU
usage of the System process is about 20%. I searched around the internet for
some information on what might be causing this and on a feeling I tried
unplugging my ethernet cable. Immediately I could see a difference:

http://img226.imageshack.us/my.php?i...pluggedje6.jpg

There, you can see that the CPU usage is down at around 2-3% where it should
be. Also, the System process is now using only 0.05% average CPU. This is a
very noticeable difference.

I next upgraded my Broadcom Ethernet drivers to 10.8.0.0 from 9.3(?). This
did not change anything. Using Sysinternal's Process Explorer, I discovered
the particular thread which used the majority of my CPU:

http://img20.imageshack.us/my.php?image=ntkrnlpagt0.jpg

The ntkrnlpa.exe!ExQueueWorkItem+0x1db threaed or similar uses up to 30% of
my CPU when the Ethernet cable is plugged in.


I don't know what the cause of this problem is or when exactly it started.
I have done virus scans and used Windows Defender and have not found any
viruses/spyware that may be causing this issue. It seems like it might be
the driver but I don't know. This problem is causing my computer to run hot
and slower and I would like to fix it. Has anyone experienced a simliar
problem or know how to fix mine? Any help would be greatly appreciated.

[mario61]

same problem. did extensive and careful diagnostics. solution: deinstalling cisco VPN client. possible reason: a) cisco VPN adds some net infrastructure, b) might be that system bombards with bytes net cards from beginning of the net-table, and it takes a while to detect non-responding cisco virtual card.
painful, took many hours.

[pescadorsp]

I found a solution for the exact same issue happened with me. Base in the last response when uninstalling VPN fixed, I went to the control panel => Network and Sharing Center => Manage Network Connections.

Select the Ethernet connection that is causing the high CPU load, right click and select properties:

Unselect just leave only the protocols and services you need. In my case, I left only "Client for Microsoft networks" and "IPv4" activated. Then the miracle happen and your CPU go to 1/2% load.

I left all VPN protocols and services activated for my wireless connection that is not causing this CPU load issue and is the only connection that I use for VPN.

In case you need to use VPN trough your Ethernet connection, you are in trouble, it's a issue between the VPN client/protocols and the Ethernet driver.

Good luck!