99-100% Explorer Processor Usage

B

brayogee

Hi,
Have a problem where computers running a custom application are
experiencing machine freezes with Explorer.exe running at 99-100% CPU
usage for extended periods.This renders the custom application
unusable.

The workaround is to kill the explorer.exe process or reboot the
machine. This incidents seem to be of a random nature and occur on
multiple PCs. The OS's on this PCs are Win2K and WinXP SP2.

Following is a list of findings so far as to the possible causes of
this problem. None of them seems to have eliminated the incidents I'm
reporting:-

1. Hardware device or undetected hardware problems e.g. USB devices
2. Presence of a virus which takes on the form of explorer
Ref: http://www.computing.net/security/wwwboard/forum/14619.html

3. Bugs with anti-virus programme updates like OfficeScan/TrendMicro
e.g. Ref:
http://esupport.trendmicro.com/support/viewxml.do?ContentID=en-124264

4. Presence of a corrupt AVI file on the server or client PC(s)
Ref: http://www.beyond3d.com/forum/archive/index.php/t-8540.html

5. A bug with Microsoft products where Explorer.exe uses 100 Percent of
the CPU When You Right-Click an Item in Windows Explorer.
Ref: http://support.microsoft.com/?kbid=837115

6. A bug with Microsoft products where Windows Stops Responding When
You Click a Large AVI File in Windows Explorer.
Ref:
http://support.microsoft.com/default.aspx?scid=kb;en-us;822430&Product=winxp

Is there anyone else who has experienced their Windows Explorer running
at 99-100% CPU usage? If so, what measure(s) were successfully
undertaken to address this?

As I look deeper into this issue, I'd appreciate any further
information based on your experiences with this issue.

Thank you.
 
B

brayogee

Thanks.

Looking at screenshots when the reported problem occurs, the
application runs as a single separate process whose CPU usage and
memory consumption is normal. The abnormality lies on the separate
explorer.exe process which consumes 99-100% CPU.

Query: Using this tool, in a Treeview format view and the listing off
explorer.exe, how can one know exactly which application is making
Windows Explorer misbehave?
 
J

JS

Click on the process that running at 99%, once it highlighted, right click
and from the options listed select: google
This should display what out there on the web about the process.

JS
 
B

brayogee

Cool. Will update with info once received on the 99-100% CPU usage
scenario for the benefit of all.
 
B

brayogee

The process that runs at 100% is 'explorer.exe' and is represented as
follows:

Process - explorer.exe
PID - 1564
CPU - 100.00
Description - Windows Explorer
Company Name - Microsoft Corporation

Right clicking the selected process and selecting 'google' takes one to
the following link:
www.google.com/search?q=explorer.exe

This turns out to be general details about 'Windows Explorer' but
nothing specific in regards to what is causing the 99-100% processor
usage.

Is there more to how one can use this tool to identify what is causing
Windows Explorer consume 99-100% CPU usage?
 
J

JS

When running Process Explorer the first column is labeled 'Process', in this
column you will find a process named Explorer.
Did you click on the + symbol to the left of Explorer to list what running
under this?

JS
 
B

brayogee

Yes.
The following processes are pegged to it:

hkcmd.exe
ACIntUsr.EXE
PccNTMon.exe
qttask.exe
internat.exe
OSA.EXE
Winword.exe
procexp.exe

The tool expressly indicates the 'parent'/root 'Windows Explorer' is
running at 100% CPU usage not any of the 'child' processes in the
hierachy.
 
B

brayogee

Comparing two incidents of the 99-100% persistent processor usage, the
following processes are common:

1. hkcmd.exe
2. ACIntUsr.EXE
3. PccNTMon.exe
4. OSA.EXE
 
B

brayogee

Nothing other than a gut feeling makes me feel 'PccNTMon.exe'
(anti-virus) is the cause even if the tool isn't indicating this.

How can one use to tell the exact process causing this using the tool?

Currently having to incremental eliminate this processes as issues on
very busy site machines(not the easiest sell)
 
J

JS

If this PC is very busy as you indicated (and a possible web server?) and
there is a lot of file activity, this will cause Trend Micro's PccNTMon real
time scanner to constantly scan and slow things down considerably.

JS
 
B

brayogee

Tx. Just some pertinent details:-
- The PC host a 'fat client'/2-Tier Windows application where the main
processing is carried out on the client front-end. These PCs are 'busy'
in that one can't unavail them for test purposes.
- The PC doesn't act as a web server.
- CPU usage hits 99-100% even where the PC has the custom application
installed but the PC has been left idle for a while.
- OS in highlighted cases were Win2K SP4

1. Of the four common and hence suspect processes when the issue occurs
ie. hkcmd.exe, ACIntUsr.EXE, PccNTMon.exe and OSA.EXE, what could
trigger the suspected 'PccNTMon.exe' process to misbehave even when the
PC is 'idle'?

2. Can one use 'Process Explorer' further to investigate this?
 
J

JS

One other thing, take a spare PC that has the FAT client installed and
exhibits the problem you described. Remove the client from this test bed PC
and see if the CPU is bogged down without the client installed.

I'm assuming that this client pulls a large chunk of data from somewhere and
then processes it on the local PC. It's possible that this client even
during non-user activity does some house keeping.

JS
 
B

brayogee

Looking at a third incident on a separate PC of 'explorer.exe' hitting
99-100% CPU usage and persisting there, the four processes indicated in
my update of 'Thurs, Jul 13 2006 6:05 pm' on this forum have been
narrowed to two i.e. :-
(a) PccNTMon.exe
(b) OSA.EXE

The other two were without linkage to Windows Explorer when this
incident occurred. I suspect (a) above.
 
J

JS

Process Explorer allows you to Kill a process (PccNTMon.exe) by right
clicking and selecting Kill. This will allow you to test you suspicions.
Keep in mind that the next time you boot PccNTMon.exe will be back.

JS
 
T

therightangledesign

Hi guys,

I got rid of the problem by getting the windows updated with the latest
microsoft windows xp updates manually by going to the microsoft
windows xp support website.
I felt after the latest WGA the updates were not hapenning
automatically.

all the best
- flavourboy
 
B

brayogee

Kul. For these incidents, Windows updates are active on the affected
PCs. I think the following dual approach could help this investigation:
- Killing the suspect process and monitoring it's effect on the
'explorer.exe' CPU usage when the problem occurs, as was suggested .
- On a select PC (affected by the issue), killing the suspect process
and monitoring if any Windows Explorer 99-100% CPU usage is reported.
 
B

brayogee

1. The 'Filemon' tool looks useful by preliminary indications. Will
explore its use. Looking at the Read/Write elements when the issue
occurs on a PC could provide leads.

2. Downloaded the trial version of the OfficeScan. Though not an exact
match to that presenting possible issues on the affected PCs it could
provide useful pointers. So far however I've not managed to get the
'explorer.exe' 99-100% CPU issue.
 
J

JS

You'll get there, it just a process of elimination. Sometimes it's something
you didn't even think of.
Keep plugging.

JS
 

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