Windows 7 not starting. Safe-mode hangs on classpnp.sys

Theycallmedarrk · Mar 2, 2015

Hello tomshardware community,
Hopefully you can help me with some issues that I have been having as detailed below:

For the last couple of days, my computer has been tremendously slow at starting up (on a 128GB SSD almost filled to capacity). My power has also gone out at least once, possibly twice in that time due to severe winds and my computer is now failing to start windows completely, hanging on the 'starting windows' screen.

When run in safe mode, the computer hangs when loading CLASSPNP.sys in system32\DRIVERS. I also tried the system recovery both in the F8 menu and on the Windows 7 install disk to which none of the three drives (including the boot drive) are displayed even though they are all detected in BIOS and the boot drive selection menu.

I tried to use the windows 7 install disk to try to wipe one of the drives and do a fresh install on it, but when I click install, it hangs on the 'starting setup' screen. This drive (a secondary drive with duplicate files of the other secondary drive) can be wiped, but the other two have crucial files that, upon deletion, would take an extremely long time and data usage (it's over 1.4TB of my programs, digitally owned games, photos, videos, music etc.), so wiping this has to be an absolute last resort.

Also, is there some program or antivirus that you would recommend to prevent these errors from re-occurring?

Thank you,
Rylan

Darkbreeze · Mar 2, 2015

To start with, anytime you make an attempt to repair, reset, refresh or install the OS, all secondary drives should be disconnected. Second, you should never have other drives that also have fully installed operating systems on them connected to the same computer as your primary drive that contains the OS. There is too much potential for confusion to the bios when it looks for the boot partition. You may also have boot partitions that are hidden, left over from previous installations, if you did not delete all existing partitions on the drive when you last installed. Windows should be installed to a drive entirely made up of unallocated space, that has not yet been formatted since deleting the existing partitions.

During the installation process, windows will create any necessary partitions and format the partition with the correct file system for it's version. If you've had several power outages and now are having issues, it's likely due to a corruption of the OS or boot partition. You will likely need to do a clean installation using the method outlined at the link provided below, but try the steps at the link above that first.

https://social.technet.microsoft.com/Forums/windows/en-US/566cdd43-ce91-4e64-93e0-8d09d8fc1ea0/windows-7-fails-to-go-into-safe-mode-stuck-at-classpnpsys?forum=w7itprogeneral

Windows 7 Clean install:

http://www.sevenforums.com/tutorials/1649-clean-install-windows-7-a.html

Also, unplug all secondary or external drives to see if possibly any of them are responsible for the issues. Generally classpnp.sys errors only occur when the related files are corrupted or missing.

And by the way, they call me dark too. Heh.

Theycallmedarrk · Mar 3, 2015

Thank you for your response!

I left my computer starting up overnight to see if it would resolve itself. It has started windows so I can finally access my files and such.

For anyone wanting to know how I will follow it up to iron out the existing errors:

I now understand that one (or both) of the secondary drives could have some windows install files made prior to installing on the SSD, so I will take the important files from them to back them up onto an external hard drive then wipe them both.
After that, I will disconnect them from the machine and backup the program files from the SSD before doing a fresh install on it.
This essentially gets rid of almost - if not all potentially corrupt windows files while still keeping my personal files.

Thank you for your help, dark

(funny coincidence haha)

Darkbreeze · Mar 3, 2015

Also, make sure that by "wipe", you mean delete the partitions on the drive, not just formatting the primary partitions on the drive. Any system reserved or boot partitions present on secondary drives (Or primary for that matter) will not be removed unless you delete all the partitions until only unallocated space remains, then format the unallocated space (Not for OS target drives. Storage drives.) in your preferred, most likely NTFS, file format. You can do this easily using disk management in administrative tools.

http://www.howtogeek.com/101862/how-to-manage-partitions-on-windows-without-downloading-any-other-software/

Of course, it should go without saying to be sure and back up any important data on any drives before doing so. If you have more than one drive to manage, you can copy all your important data over to one drive, delete the partitions on the other drive and get it set up, then copy the data back to that drive and do the same management to the other drive.

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Windows 7 not starting. Safe-mode hangs on classpnp.sys

Theycallmedarrk

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Darkbreeze

Darkbreeze

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Theycallmedarrk

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Darkbreeze

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