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Windows 7 No Boot - STOP: 0x0000007B and CLASSPNP.SYS problem?

    Question

  • Hello helpers,

    I have a W7 Pro 64 machine (Dell). Two days ago, all programs became very sluggish/hung up, so I restarted in an attempt to set things right.

    Ever since then, Windows has not booted.  It goes to the Windows Recovery, but it cannot locate the Windows OS to repair/recover.  Viewing the Boot Log, it hangs on CLASSPNP.SYS. 

    The BSOD it throws has the error message:  STOP: 0x0000007B (0xFFFFF880009A9928, 0xFFFFFFFFC0000034, 0x0000000000000000, 0x0000000000000000)
     

    These threads outline my exact problem (http://www.overclockingwiki.org/forums/showthread.php/6052-O-K-I-m-Stuck!! and http://social.technet.microsoft.com/Forums/en/w7itprogeneral/thread/b950c21f-46f4-4011-99f6-00e9c2780170).  This is apparently a semi-well known issue.  I found one fix that seems to work for most, which entails copying the CLASSPNP.SYS file from another system and copying it to the crippled machine (while renaming the original CLASSPNP.SYS.OLD or something along those lines).  I have done this, but to no avail. 

    I have run all diagnostics on the drive, no errors.  I've also tried changing from AHCI mode to ATA in CMOS, but again no results.

    Please help if you can, I have no idea what to try next besides a clean install and I really would rather avoid that.

    • Edited by Oversight Friday, July 09, 2010 8:00 PM TItle too long
    Friday, July 09, 2010 7:57 PM

Answers

All replies

  • If you would have searched either the Microsoft website or the internet you would have discovered that the 0x0000007B is a very well know error for the system not being able to find the boot device.  You are either missing a driver for your hard drive controller or it is corrupt.

    See info @ http://pcsupport.about.com/od/findbyerrormessage/a/stop0x0000007b.htm

    Friday, July 09, 2010 8:29 PM
  • I did search, hence my linking of the MS forums lol...

    I've looked over that link you posted as well, and I have ruled out or tried each option (besides replacing the hd).  I know the problem.  I don't know the solution.

    I have also updated the BIOS, tried recovery with the W7 disc (failed), checked all physical connections, used an alternate CLASSPNP.SYS.  I am in the process now of trying to update my HD firmware if it exists.  If that doesn't work, I'm stumped.

    Rick do you know of any way to update the drive controller in the DOS environment?

     

    Friday, July 09, 2010 9:48 PM
  • I don't know of a way to update the driver in the DOS environment.  If you look at the links for STOP: 0x0000007B @ http://search.microsoft.com/results.aspx?form=MSHOME&mkt=en-US&setlang=en-US&q=STOP%3a+0x0000007B you will see that it is almost exclusively a driver problem.  I did note at one of your links you posted that one person found they had a virus that had corrupted some files causing the 0x0000007b error.  There are offline scanners you can get.  One is Vipre Rescue @ http://live.sunbeltsoftware.com/

    I think the CLASSPNP.SYS is a Red Herring and should be ignored with the exception that it may have caught a virus.

    Friday, July 09, 2010 10:07 PM
  • Hello Oversight:

     

    This “STOP: 0x0000007B” message shows when there are Boot-Sector Viruses, Device Driver Issues, Hardware Issues and other issues. The situation you mentioned that in the Boot Log, it hangs on CLASSPNP.SYS. This Classpnp.sys is the driver for SCSI devices, due to the Windows cannot be booted, this problem may occur in scenarios as following:

     

    ·         The registry is corrupted.

    ·         A System file is missing or damaged.

    ·         A device driver file is missing or damaged.

     

    In this case, you need to do a Startup Repair and System Restore from DVD to fix this issue. Find how to run the startup repair tool by using Windows 7 installation disc:

    http://support.microsoft.com/kb/925810

     

    You can also learn more details here: Error message when you start a Windows 7 or Windows Vista-based computer after you change the SATA mode of the boot drive: "STOP 0x0000007B INACCESSABLE_BOOT_DEVICE"

     

     

    Hope it can help you!

     

    Best regards,

    Miya Yao

    Tuesday, July 13, 2010 7:57 AM
  • Miya,

    I did a test restore from a known good backup to a different machine.  This is a legitimate scenario, and fortunately, I tested before a failure occurred. It should absolutely be conceivable that customers might restore from a non-SATA machine to a SATA containing machine. 

    This should not be a customer issue.  Instead, it should be dealt with by the O/S (at an engineering level).

    Friday, March 18, 2011 1:17 PM
  • Miya,

    I did a test restore from a known good backup to a different machine.  This is a legitimate scenario, and fortunately, I tested before a failure occurred. It should absolutely be conceivable that customers might restore from a non-SATA machine to a SATA containing machine. 

    This should not be a customer issue.  Instead, it should be dealt with by the O/S (at an engineering level).

    So, what did you discover.  Your post is about as clear as mud.

    Restoring a back-up from a non-SATA machine to a SATA machine is not a common scenario because there is a high probability that the overall hardware would have changed significantly so that a clean re-install would be necessary.

    And where does the OP ever mention he is going from a non-SATA machine to a SATA machine?


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”
    Friday, March 18, 2011 2:07 PM
  • You put this up twice but since it doesn't always work what else is there to do? especially for a laptop?
    • Proposed as answer by HugoCore Monday, December 26, 2011 6:57 PM
    • Unproposed as answer by HugoCore Monday, December 26, 2011 6:57 PM
    Wednesday, June 29, 2011 8:32 PM
  • I had also Windows 7 with 0x0000007B blue screen while loading Windows 7.

    It's turn out that the BIOS had been change to another disk mode, IDE, ex-raid. For now I wanted IDE, to be simple.

    Here's what works with me:

    In the BIOS, i went change the SATA to IDE mode (NOT RAID, NOT AHCI)

    1.Boot Win7 DVD

    2.Choose the Language Selection.

    3.Choose Repair.

    4.On the recovery tools choose the Command Line Console

    5.Type:regedit <ENTER>

    7.Highlight HKEY_LOCAL_MACHINE

    8.File > Load Hive

    9.Select < windows partition with problem > \Windows\System32\config\system (Backup this first, it's advised)

    10.Regedit will ask for a Key name: Name it something like "temp"

    11.Located HKEY_LOCAL_MACHINE/temp/Select/Current

    12.Searched for every key containing the value “SCSI Miniport” where the "Start" value was a "3" and changed the "Start" value to a "0". (F3 to search next result).

    13.Highlight "temp"

    14.File > Unload Hive

    15.Restart

    16.Enter in Win7 :)


    Based on: http://www.askvg.com/how-to-change-sata-hard-disk-mode-from-ide-to-ahci-raid-in-bios-after-installing-windows/

     


    Core
    • Edited by HugoCore Thursday, December 29, 2011 7:54 PM Missing introduction.
    • Proposed as answer by mback2k Sunday, October 28, 2012 11:17 AM
    Monday, December 26, 2011 7:11 PM
  • Here's what works with me:

    In the BIOS, i have SATA with IDE mode (NOT RAID, NOT AHCI)

     

    1.Boot Win7 DVD

    2.Choose the Language Selection.

    3.Choose Repair.

    4.On the recovery tools choose the Command Line Console

    5.Type:regedit <ENTER>

    7.Highlight HKEY_LOCAL_MACHINE

    8.File > Load Hive

    9.Select < windows partition with problem > \Windows\System32\config\system (Backup this first, it's advised)

    10.Regedit will ask for a Key name: Name it something like "temp"

    11.Located HKEY_LOCAL_MACHINE/temp/Select/Current

    12.Searched for every key containing the value “SCSI Miniport” where the "Start" value was a "3" and changed the "Start" value to a "0". (F3 to search next result).

    13.Highlight "temp"

    14.File > Unload Hive

    15.Restart

    16.Enter in Win7 :)


    Based on: http://www.askvg.com/how-to-change-sata-hard-disk-mode-from-ide-to-ahci-raid-in-bios-after-installing-windows/

     


    Core


    HugoCore,

    What does your post have to do with the original post?  The original post is asking about the 0c7B error.  Your information has no relationship to a 0x7B error.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”
    Monday, December 26, 2011 8:02 PM
  • Rick Dee,

    I have changed the post. I was also having 0x7B problem. It's turns out that the reason was, changing the disk mode in BIOS create this error.

    Hope this help's some one.

    Ps. Once again, 7B error Based on: http://www.askvg.com/how-to-change-sata-hard-disk-mode-from-ide-to-ahci-raid-in-bios-after-installing-windows/

    Best Regards


    Core
    • Proposed as answer by RTKIII Thursday, April 25, 2013 5:16 PM
    Thursday, December 29, 2011 7:58 PM
  • well ive been seareching and searching for answers. HugoCore your fix was the one i needed. I tried registry tricks. but to no avail. This one worked perfect! thx

    Monday, July 16, 2012 9:36 AM
  • Hi

    I just had this problem on my dell and reading the posts decided to try something different. I disabled all my drives bar my original boot drive- I had 2 windows 7 partitions and both showing this issue and 3 drives. 

    I disabled my RAID array tried a boot -failed and then re-enabled my RAID array and the system managed to boot fine.


    • Edited by spud Wednesday, February 20, 2013 12:20 AM
    Wednesday, February 20, 2013 12:19 AM
  • Hi Hugo!

    Thank you, you saved my day! This absolutly works. And sorry RickDee, but this has to do with the problem.

    I had a mainboard crash and bought a new mainboard. I just changed the mainboard and kept all the rest (CPU, RAM, HDD etc.). My WinXP in my first partition booted fine, but needed some time to reinstall all the drivers. But my Win7 on the second partition always crashed with this BSOD. But thanks to the help of Hugo, my Win7 started fine and now everything is perfect again!

    Regards,
    red


    • Edited by der_red Friday, March 01, 2013 6:49 PM
    Friday, March 01, 2013 6:49 PM
  • I have put this reply here because it is the most recent thread discussing this problem I can find, I have posted this reponse elsewhere.

    I have been reading other threads to try and fix this and was not looking foward to rebuilding PC but I got lucky. Suggest you try this for yourselves as it worked for me.

    • Reboot in Safe Mode with Command Prompt
    • When the boot script freezes at "CLASSPNP.SYS" line hit <ctrl><break>
    • When I tried this it killed the frozen command line session and then Windows went on to reboot in safe mode
    • I then restarted in normal mode and hey presto no more problems
    • Not yet anyway

    What a surprise that an old MSDOS keyboard command seems to be able, at last in my case, to fix what appears to be a significant Windows problem for so many...

    Makes you think

    Hope this saves a few people from having to do major reinstall work or hardware fixes

    • Proposed as answer by BrettLas Monday, June 16, 2014 2:06 AM
    Wednesday, March 06, 2013 8:57 PM
  • Hugo's suggestion worked for me as well.  I did not mess with the BIOS but booted to WIN7CD and then ran through his instructions.  Win7 booted and re installed all the devices upon login..THANK YOU!!!!!

    I had exhausted all other normal options and I was like 'Might as well try this."  WORKED!!!!

    thank you!

    Thursday, April 25, 2013 5:15 PM
  • Hugo's method worked!

    thanks

    Friday, April 26, 2013 7:22 PM
  • Hello,

    I tried all the things mentioned in this and different threads all over the net. None of them has the solution. After some trying this approach helped me:

    Boot in restore mode and changing the active ControlSet registry entry manually:

    1. Boot from Windows DVD or enter extended start mode
    2. On the recovery tools choose the Command Line Console
    3. Type:regedit <ENTER>
    4. Highlight HKEY_LOCAL_MACHINE
    5. File > Load Hive
    6. Select < windows partition with problem > \Windows\System32\config\system (Backup this first, it's advised)
    7. Regedit will ask for a Key name: Name it something like "temp"
    8. Locate HKEY_LOCAL_MACHINE/temp/Select
    9. Note the value in "LastKnownGood"
    10. If this value is different from the value in "Current", change the "Current" value to the one in "LastKnownGood"
    11. Do the same with "Default"
    12. Select "temp", then "File" -> unload hive
    13. Reboot to normal Windows
    14. Windows is starting as usual

    Hope this helps someone!

    Best regards

    Gerrit

    • Proposed as answer by sub400 Sunday, December 22, 2013 10:51 PM
    Sunday, June 09, 2013 11:56 AM
  • Hey Gerrit,

    kisses all over :) you've just saved my week. That was the solution. Does anyone have an idea why that entries changes without really changing the BIOS settings?

    Kind regards

    JD

    Monday, July 08, 2013 8:30 AM
  • The problem with the internet is people posting that are clueless.  Why post if you don't know.

    The original question was that the boot disk had been moved to a different controller, requiring a different boot time driver.

    Only the driver of the boot device is loaded special early in the boot process; all other disk controllers are loaded the normal way.  What the documented method does is tell windows to start the needed driver for the controller that the boot disk is attached to EARLY (special) in the boot process.

    To answer your post - THIS IS THE EXACT SOLUTION REQUIRED.

    Your comment shows that you know nothing about the problem, you probably were so simplistic, you thought that to correct a stop 7b would require changing a setting in the bios, which shows how little you know.

    Many of us don't know many things in life.  I don't go on doctors forums offering my opinion on how to do brain surgery.  Don't post such stupidity.  Making yourself look stupid (you did) is your business, but it impedes others.

    Imagine if the poster did NOT try the posted solution that you slammed, BECAUSE you slammed it as stupid!!!!

    Tell me - how would YOU fix it - sure your expertise.

    Wednesday, October 02, 2013 10:09 PM
  • I have tried all suggested solutions, but I still can't seem to boot into the windows I need to be in. My hardware situation is like this (simplified):

    Drive1 on inch10r > Boot loader and a now recovered old version of windows 7

    Drive2 on Marvell 91xx in AHCI mode ( Asus U3S6 pci-e card) > Windows that refuses to boot. 0x0000007B (0xFFFFF880009A9928, 0xFFFFFFFFc0000034, 0x0000000000000000, 0x0000000000000000) error code. 

    Windows repair first found a corrupt msahci.sys, said problem is fixed and to reboot, then a corrupt slui, again said problem solved and reboot, but neither things solved the problem, the 3rd time it couldn't repair the problem. 0x0 error

    What windows repair did do is repair an old windows 7 install from 2011, where I installed all drivers now and try to use it as a comparison.

    What I noticed is that somehow mv91xx.sys had been removed from Windows\System32\drivers, so I copied it from the working windows 7 to the one that isn't working. No idea how this happened, but somehow the Marvell driver has been removed.

    When comparing the registries of the 2 Windowses, what I notice is that the one that doesn't work, doesn't seem to have HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\msahci\Enum and HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\mv91xx\Enum while the one that does work does have them, what do these folders contain ? I mean, there is a mshci and mv91xx folder, but both do not, unlike in the working windows, contain ''Enum'' and its contents.

    Other info :

    ntbtlog is not written, the ntbtlog I have is from a year ago when I used it out of curiosity. There is no minidump either. I have not changed anything hardware wise in the past months and windows suddenly stopped booting 3 days ago. The windows I'm trying to recover is not on the same drive as the MBR/Boot selector. (The total hardware config&software is complex, I now have 2x windows 7, one of which I managed to recover from 2 years ago, and the one that stopped working, and also a still working windows XP install on an even different drive ( pc has 8 hard drives...). Last known hardware config doesn't work, neither does Gerrits trick.

    Any ideas how to force a driver into windows without booting into it ? I can boot into another copy of windows thus I have access to a working set of files and drivers on this specific hardware setup.

    I have not yet tried to put the drive on to the mainboard sata controllers as a try, but the reason for that is because it's an SSD that happens to ( very slightly) perform better on the Marvell sata3 controller than the onboard sata2 ones so I want it to run off that... Though might be worth a try see if it finds the SSD on the onboard controller instead of the marvell?

    EDIT: I have now tried the SSD on the mainboard, both in AHCI and IDE modes, still same BSOD and windows error repair thing doesn't know a solution. GRRRRR.

    Anyone have any suggestions for me to try ? Is it possible to do an upgrade install of windows without booting into it initially ? Or do you have any other suggestions ?


    • Edited by snovvdog Sunday, November 03, 2013 7:41 PM
    Sunday, November 03, 2013 7:05 PM
  • I have tried all suggested solutions, but I still can't seem to boot into the windows I need to be in. My hardware situation is like this (simplified):

    Drive1 on inch10r > Boot loader and a now recovered old version of windows 7

    Drive2 on Marvell 91xx in AHCI mode ( Asus U3S6 pci-e card) > Windows that refuses to boot. 0x0000007B (0xFFFFF880009A9928, 0xFFFFFFFFc0000034, 0x0000000000000000, 0x0000000000000000) error code. 

    Windows repair first found a corrupt msahci.sys, said problem is fixed and to reboot, then a corrupt slui, again said problem solved and reboot, but neither things solved the problem, the 3rd time it couldn't repair the problem. 0x0 error

    What windows repair did do is repair an old windows 7 install from 2011, where I installed all drivers now and try to use it as a comparison.

    What I noticed is that somehow mv91xx.sys had been removed from Windows\System32\drivers, so I copied it from the working windows 7 to the one that isn't working. No idea how this happened, but somehow the Marvell driver has been removed.

    When comparing the registries of the 2 Windowses, what I notice is that the one that doesn't work, doesn't seem to have HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\msahci\Enum and HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\mv91xx\Enum while the one that does work does have them, what do these folders contain ? I mean, there is a mshci and mv91xx folder, but both do not, unlike in the working windows, contain ''Enum'' and its contents.

    Other info :

    ntbtlog is not written, the ntbtlog I have is from a year ago when I used it out of curiosity. There is no minidump either. I have not changed anything hardware wise in the past months and windows suddenly stopped booting 3 days ago. The windows I'm trying to recover is not on the same drive as the MBR/Boot selector. (The total hardware config&software is complex, I now have 2x windows 7, one of which I managed to recover from 2 years ago, and the one that stopped working, and also a still working windows XP install on an even different drive ( pc has 8 hard drives...). Last known hardware config doesn't work, neither does Gerrits trick.

    Any ideas how to force a driver into windows without booting into it ? I can boot into another copy of windows thus I have access to a working set of files and drivers on this specific hardware setup.

    I have not yet tried to put the drive on to the mainboard sata controllers as a try, but the reason for that is because it's an SSD that happens to ( very slightly) perform better on the Marvell sata3 controller than the onboard sata2 ones so I want it to run off that... Though might be worth a try see if it finds the SSD on the onboard controller instead of the marvell?

    EDIT: I have now tried the SSD on the mainboard, both in AHCI and IDE modes, still same BSOD and windows error repair thing doesn't know a solution. GRRRRR.

    Anyone have any suggestions for me to try ? Is it possible to do an upgrade install of windows without booting into it initially ? Or do you have any other suggestions ?


                                                                                                snowdog

    Important Note:  It is not proper internet etiquette to hang a new problem on a 3 year old thread, especially when your situation does not math the original post exactly.  If you really want your problem to get attention, start you own new thread.

    I suggest you configure your system with one, and only one, HDD or SSD and install Windows 7 from scratch.  To me your post is a bit confusing about your configuration, but you really need to contact the Technical Support of your system motherboard to ensure what you're trying to do is a supported configuration. Not all motherboards support booting from the secondary SATA chip, Marvell in this case, and I have seen many posts of people reporting problems with the Marvell drivers. 


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”

    Monday, November 04, 2013 11:48 AM
  • Na bios mude para modo ide. 

    Saturday, November 30, 2013 11:25 AM
  • Thank you so much, saved my day!
    Sunday, December 22, 2013 10:55 PM