fatal error on startup

[Lorne]

On my desktop I am running XP home with service pack 3 and all updates. It
was working fine yesterday and I have not knowingly installed any software
or changed any hardware for at least a month (except windows updates).

Today I got an svhost error on startup - "Instruction at 0x83fffffd
referenced memory at 0x83fffffd. The memory could not be written"

Shortly later it froze so I rebooted, getting the error
"IRQL_NOT_LESS_OR_EQUAL".

After several unsuccessful tries to reboot I used F8 and selected latest
known good configuration. It seemed to start OK then I got the svhost error
again.

Every time I reboot I get an error. Sometimes svhost (always the same
memory addres), but also "service executable experienced an error and has to
close". It seems to start OK in safe mode. Also if I leave the svhost
error message window open the computer seems to work - only when I press the
OK button (which I hguess shuts down the svhost service of which about 5 are
running) does it hang.

Can anyone tell me what the likely problems are and how to solve it?

A good starting point may be to find which instance of svhost is causing the
memory write error and what process opened it - any ideas there?

McAfee and windows defender are not reporting any viruses or unwanted
programs.

 

[JS]

Svchost:
From Ramesh's web site: http://windowsxp.mvps.org/svchost.htm
Also: http://support.microsoft.com/?kbid=314056

To find out more about Svchost.exe entries try Process Explorer:
http://www.microsoft.com/technet/sysinternals/SystemInformation/ProcessExplorer.mspx

Once you have Process Explorer installed and running:
In the taskbar select View and check 'Show Process Tree' and 'Show Lower
Pane' options.
(This will provide some of the detailed info you may need)
Expand the Process tree until 'Services.exe' has been expanded.
Next move the mouse cursor over the Svchost.exe process that you are
interested in.
Or expand the Svchost entry if you see a + sign to the left of Svchost
entry.
(You should now see a pop up with a list of services associated with the
Svchost.exe you selected)
Next double click on the Svchost.exe process that you are interested in.
The 'Properties' Window should now be displayed with numerous tabs
available.
(Two important tabs to look at are: Services and Environment)

IRQ_NOT_LESS_OR_EQUAL:
Could be a device driver problem.
Check 'Device Manager', look for any devices that have a tick mark.
Also use Event Viewer to check the event logs.

JS

 

[Lorne]

Thanks for the link. It may help but at the moment I can't get it to boot
reliably. I tried a system restore to a points saved 2 weeks ago and it
does often boot but then gets an error after a couple of minutes and shuts
down.

If I then reboot it does not find the hard disk so I have to switch off the
power first - then it does find the disk but 3 times out of 4 will not boot
completely. I get different errors sometimes one about a page file in a non
page area and another saying McAfee will not start, another saying
MsMpEng.exe could not read memory at some location, sometimes service
executable had a problem and has to close.

I also get an icon in the system tray saying it can't complete genuine
windows verification, but if I click it I go to the web site and get a
message thanking me for using genuine software!

Sometimes I also get a windows defender icon saying it is 2 years outof date
but then next time it is fully updated!

Its all very confusing and different every time I boot. Is there any clue
in all this that points to the cause? It looks like svchost started it but
now I have a host of other issues.

 

[JS]

Try running Memtest86+,
This runs from a boot disk or CD and should eliminate or
confirm if your ram is causing the problem.

Let it run for as long as you can, 2,4,6,8 or more hours,
if no errors by then your ram is OK.
See: http://www.memtest.org/

JS

 

[AJR]

Lorne - a multiple of errors/problems as you detail make malware/virus a
suspect.

Also try booting into Safe Mode (F8 Mneu Option) to run an anti-virus
utility.

 

[Lorne]

I have faulty RAM (886 errors on one module, oher OK) - thanks for help

 

[JS]

Can't hurt to check to see if the memory stick is fully inserted.

JS