Windows 7: BSOD with System Service Exception, CLASSPNP.SYS

Sarmadsh · 08 Dec 2012

hello all,

im using windows 7 ultimate 64 bit on my Intel Core i5.

im having random BSODs. the blue screen stays for seconds and then the system restarts.
in safe mode, before start up, the driver list often stops at CLASSPNP.SYS.
the SYSTEM_SERVICE_EXCEPTION appears sometimes on the blue screen but not always..
kindly help
im attaching the minidump files.
thanks

Sarmadsh · 08 Dec 2012

update:

sorry forgot to mention my system details

windows 7 Ultimate (64 bit)
Intel core i5-2500K CPU @ 3.30GHz
4GB RAM
64 bit operating system
Realtek HD Audio
Intel R HD Graphics family

Sarmadsh · 10 Dec 2012

hello all,

im using
windows 7 Ultimate (64 bit)
Intel core i5-2500K CPU @ 3.30GHz
4GB RAM
64 bit operating system
Realtek HD Audio
Intel R HD Graphics family

im having random BSODs. the blue screen stays for seconds and then the system restarts.
in safe mode, before start up, the driver list often stops at CLASSPNP.SYS.
the SYSTEM_SERVICE_EXCEPTION appears sometimes on the blue screen but not always..
kindly help
im attaching the minidump files.
thanks

**koolkat77** · 10 Dec 2012

Welcome to SevenForums.

Please uninstall Avast! antivirus, it's contributing to your blue screens.

avast! Uninstall Utility | Download aswClear for avast! Removal

MSE is recommended from a strict BSOD perspective, compatibility & stability compared to other antiviruses/internet security software:-

1. Microsoft Security Essentials - Free Antivirus for Windows
2. Malwarebytes - Free
3. Good and Free system security combination.

Do not start the free trial of Malware Bytes; remember to deselect that option when prompted.

Run a full scan with both (separately) once downloaded, installed and updated.

Install all updates including SP-1:

Learn how to install Windows 7 Service Pack 1 (SP1)

If you are overclocking your system, please return all overclocked components to their stock speeds. If the BSOD's are found not to be caused by the overclock, you can re-overclock the components once we have finished the diagnostics.

Code:

Start Menu\Programs\ASUS\AI Suite II	Public:Start Menu\Programs\ASUS\AI Suite II	Public
Start Menu\Programs\ASUS\Disk Unlocker	Public:Start Menu\Programs\ASUS\Disk Unlocker	Public

This is overclocking software and can lead to system instability and BSOD's. Please reset all components to their stock speeds and then remove the software.

For monitoring the heat/celsius of the system, use Speccy or HWinfo:

Run the System File Checker. It allows the user to scan for and restore corruptions in Windows system files.

1. Click on the
2. Type CMD on Search
3. Left click and Run as Administrator
4. Type SFC /scannow

Full tutorial here:

SFC /SCANNOW Command - System File Checker

Run Disk Check on your hard disk for file system errors and bad sectors on it:

Disk Check

Free up the start-up, nothing except the antivirus is usually needed.

Go to this link: Intel® Driver Update Utility Check the system for latest updates. Download and install all that it finds.

*Report back if this brings more stability.

Then test RAM.

Take memtest. Run for 8 passes and test each stick in a know good slot for an additional 6 passes.

RAM - Test with Memtest86+

Quote:

The goal is to test all the RAM sticks and all the motherboard slots.

Check your motherboard manual to ensure the RAM sticks are in the recommended motherboard slots. Some motherboards have very specific slots required for the number of RAM sticks installed.

If you get errors, stop the test and continue with the next step.

1. Remove all but one stick of RAM from your computer (this will be RAM stick #1), and run Memtest86 again, for 7 passes.

*Be sure to note the RAM stick, use a piece of tape with a number, and note the motherboard slot.

If this stick passes the test then go to step #3.

2. If RAM stick #1 has errors, repeat the test with RAM stick #2 in the same motherboard slot.

*If RAM stick #2 passes, this indicates that RAM stick #1 may be bad. If you want to be absolutely sure, re-test RAM stick #1 in another known good slot.

*If RAM stick #2 has errors, this indicates another possible bad RAM stick, a possible motherboard slot failure or inadequate settings.

3. Test the next stick of RAM (stick #2) in the next motherboard slot.

*If this RAM stick has errors repeat step #2 using a known good stick if possible, or another stick.

*If this RAM stick has no errors and both sticks failed in slot#1, test RAM stick #1 in this slot.

4. If you find a stick that passes the test, test it in all the other motherboard slots.

If Part 2 testing shows errors, and all tests in Part 3 show errors, you will need to test the RAM sticks in another computer and/or test other RAM in your computer to identify the problem.

In this way, you can identify whether it is a bad stick of RAM, a bad motherboard, or incompatibility between the sticks.

Errors are sometimes found after 8 passes.

Do this test overnight, before going to bed.

Postback results.

Sarmadsh · 11 Dec 2012

Wow!
Thanks alot for all the detailed info and guidance..
Will definitely report back asap.
Thanks again

**koolkat77** · 11 Dec 2012

Take your time.
Good luck

Sarmadsh · 13 Dec 2012

so Im back.. So here’s all that I have done so far:

Avast! antivirus - removed
AI Suite & Disk Locker - removed
Windows updated (SP1 not yet installed as there were other updates needed prior to SP1 update)
A BSOD (IRQ_LESS_OR_NOT_EQUAL was the only thing I could gather for a few seconds of BlueScreen..)
MSE - Installed & Updated (Not scanned yet)
Malwarebytes - installed & Updated – scan removed some registry errors...
Windows updated with SP1.
Intel Device Drivers updated
Another BSOD..
MSE - Quick scan – no errors
MSE - Full Scan – could not be completed even after trying for 5 times over two days, every time scan gets interrupted by a BSOD…
Now:
Running System File Checker via CMD..
(A BSOD while at 20% check..)
Restarted scan.. After 100%, the CMD window says:
‘Windows Resource Protection found corrupt files but was unable to fix some of them. Details are included in the CBS log windir\logs\CBS\CBS.log’

Now im re-running the System File Checker. meanwhile im also sending u the minidump files as well...

UPDATE:
so the scan completed second time and again it says that corrupt files were found but was unable to fix some of them..
starting Disk Checks now..

**koolkat77** · 14 Dec 2012

You should proceed with memtest.

Make sure you test each stick seperately.

Sarmadsh · 05 Jan 2013

sorry couldnt post results.
memtest done.
found no errors after overnight scans on two consecutive nights...
and still i suffer the BSODs

one thing i wana mention if it may be of any value here..
when i got this system, i remember i bought a IDE-to-SATA convertor..
i wanted to transfer the date from the IDE HDD from my previous system to this one. for that, LAN connection was much too slow for file transfer..
anyway, in order to make the new system recognize the second HDD, i remember making some changes in the connections of my SATA HDD to the motherboard (i mean, i cahnged the ports a bit). Also, i had some changes done in the bios at that time regarding boot etc. i dont remember the exact changes now...
but i do remember that i reverted the changes back, as the IDE-to-SATA convertor was bad and i had removed it then..
now is there a chance that i might have made some changes in the BIOS settings that might be the reason of these BSODs?
Is there a way for me to tell u whats my BIOS settings like, and what can be wrong in it?

i think my system is a mess and out of my control

sending the latest minidumps
thanks...

**Northernsoul55** · 05 Jan 2013

Hi Sarmadsh,

If your 'BSOD does not stay on the screen for long, try these following steps:

1. Power off the computer > Power it back on > At the logo repeatedly tap F8 key > The Advanced Startup Menu will appear
2. Use the arrow keys to highlight "Disable automatic restart on system failure" then Tap 'Enter.
Note: This will not crash the system after the BSOD and will freeze it to allow you to capture the details.

Hope this helps

Cheers

Dave

Windows 7: BSOD with System Service Exception, CLASSPNP.SYS

BSOD with System Service Exception, CLASSPNP.SYS problems?