Laptop hangs up at Classpnp.sys file.

Anonymous
2009-10-30T12:33:24+00:00

So I installed Windows 7 the other night on my laptop.  I did the driver updates and installed Norton.  I also installed Office 2007.  Then I shut it down for the night.  The next day I turned it back on to install a few more things.  A friend recommended that I install Ad-Aware, so I did, and ran it.  I've used it on a few of my machines before with no problems.  I installed a couple more programs (SANDRA & CPU-ID) then I shut it down for the night.  It stalled on shutdown.  I didn't think anything about it and after about 20 minutes I did the power-off.  I started it up the next day and it now hangs at the starting windows screen.  I've tried the following with all the same results:

  • System repair - hangs at the repair screen
  • Start normally - hangs at the starting windows screen
  • Start in safe mode - hangs at the classpnp.sys file
  • Start in safe mode with command prompt - hangs at the classpnp.sys file
  • start in safe mode with networking - hangs at the classpnp.sys file

I've even tried to put in the windows 7 disc back in to do a re-install and it hangs at the starting windows screen.

It seems like no matter what I try I get the hang up at the windows starting screen.

Someone help, please!!!

Windows for home | Previous Windows versions | Windows update

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Anonymous
2009-11-08T15:10:27+00:00

So the other night I tried a few more things with all the same results.  Here's what I tried:

  • I bought a second gig of ram, so I tried swopping out one stick, then the other - same results.
  • I bought a hard drive enclosure, removed the hard drive, formatted it with another computer, made sure I could save things to it, re-installed hard drive, booted from CD - same results.
  • I bought a brand new hard drive, installed it, booted from CD - same results.
  • Put old hard drive back in with both sticks of ram - same results.

After reviewing a few things, I found that when Windows gets to the "Starting Windows" screen, it's checking your hardware to make sure that things are OK.  Well, my hard drive, RAM, CD Drive, and Video Card are OK (I get all the right video stuff), so there's only a couple of things left, and one is the motherboard.  So, I believe that there is a hardware issue that is not allowing Win7 to completely load.

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Anonymous
2010-12-13T17:26:25+00:00

Go into your bios and check the hard drive configuration.   Once I reverted back to IDE the system booted as normal.  You may have to do the opposite!!!

At all times my system hung at classpnp.sys as advertised.  Let me know if this fixed

Macbionik.com

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  1. Anonymous
    2013-04-22T08:47:27+00:00

    Right heres the fix.

    1. Hold your power button to switch of the computer.
    2. On the load hit F12
    3. Go to the bottom and hit enter(BIOS)
    4. Go across to advances and go to system config.
    5. Change the SATA controller from ACHI to compatible
    6. Hit F10 or save and exit.
    7. Then boot the computer in start up repair.
    8. You'll get stuck on the windows 7 blue screen
    9. leave it for about 5-10 mins and repair will load. Takes about 10-20 mins to find the error and can take up to an hour for it to resolve.
    10. Once its done you'll be able to get on however you may experience lack of speed.
    11. I would suggest turning of the computer and repeatadly hit F8 on the boot.
    12. On the list of options choose system reapir. Then another menu will load
    13. Choose the bottom one HDD Restore. Restore it all and put it back to factory settings. If the laptop came with windows then it will be reinstalled for you. Then boom its fine.

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  2. Anonymous
    2013-04-10T08:01:18+00:00

    Andrew, your workaround is awesome. I registered to MSN just to tell you this. God bless!

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  3. Anonymous
    2013-03-06T20:34:53+00:00

    I have been reading all the 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

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