Windows 7 fails to go into safe mode. Stuck at classpnp.sys
Hi, I wanted to go into safe mode on windows 7 but it kept stopping at classpnp.sys . After reading a few threads I read about using Msconfig and checking the safe mode option under "Boot". It still keeps staying at classpnp.sys and when I hit F8 and hit "Last Known Good Configuration (advanced)" it seems to be able to get trough and it says it's actually loading up safe mode but then it changes to a black screen and does not change from that screen. I would appreciate and information you guys have that could solve this problem. If any of you know a command I could type in cmd to bring up the msconfig while in repair mode I could fix it because all I need to do is untick "Safe mode on startup"
March 8th, 2010 7:43pm

Hello,Try the following resolution:1. Boot the computer to windows recovery mode.2. Click Commmad Prompt, type in:rename c:\windows\system32\drivers\classpnp.sys classpnp.oldNote: I assume that your windows is installed on C drive. I have tested this step, it will not crash your system.Thomas77
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March 9th, 2010 3:48am

Hello @Thomas_77I have tried your resolution with no luck. I got the blue screen of death and then the computer reset it self back to c:\windows\system32\drivers\classpnp.sysI put my comp in safe mode to install the second disc of Fallout 3. I had to do this for vista. The problem was exactly the same then. I am now running windows 7 home premium 32bit. last time while on vista the computer fixed it self and after about an hour of looping loged on under safe mode. however this time this is not happening.I get from pushing the power button till a black screen with a cursor on it. Then it starts all over again. I'm not sure what else to do. I do not have install discs for either vista or windows 7. The shop in new zealand where i brought it from says we do not need them. Any suggestions.
March 9th, 2010 4:14am

I have sort of fixed the issue on my computer. For further information check my thread Windows 7 and the classpnp.sys safe mode loop. @ Erik Soto, I am still unsure on how to install Fallout 3 Game of the year edition with out going into safe mode for the second disc. As I had to go through all I did to get this far in fixing my computer I am unwilling to try it again until I have other methods.
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March 10th, 2010 1:35am

I will try some of the things you said soon. My computer is a Gateway
March 11th, 2010 7:27pm

Hello,Try a in-place upgrade to repair the corrupted files:In-place Upgrade============= 1. Insert the Windows 7 DVD in the computer's DVD drive. 2. Click Start and choose Computer.3. Please find the "setup.exe" file in the DVD-ROM and double click it.4. Click Install now. 5. When we are prompted to input the product key, please click Next without inputting any key. The setup wizard will prompt and ask if you agree to install Windows 7 without the key. Please choose to confirm.6. When you reach the "Which type of installation do you want" screen, click Upgrade to upgrade the system files of Windows Vista.Thomas77
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March 14th, 2010 9:55pm

I cant get past the safe mode boot up. And to Limbix, I tried the Ubuntu thing but it gets stuck at the white Ubuntu sign.
March 16th, 2010 12:31am

Besides above suggestions, please also try the following steps to troubleshoot the issue. 1. Temporarily disable all unnecessary hardware devices in Device Manager, such as Modem, sound card or external device. For detail steps, we can refer to the link below: Device Clean Boot 2. Run System File Checker (SFC) to verify whether any system file is corrupted. If the issue persists, I suggest you insert the Windows 7 installation disk and repair the system. Thanks, Novak
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March 16th, 2010 4:44am

As stated before, I cant get past the Safe mode loop. It try's to go into safe mode and then crashes and restarts and then repeats. I'm thinking of just re-installing windows 7.
March 16th, 2010 4:22pm

My computer is a Gateway too. I started to have this problem after installing the Sniper Ghost Warrior game. After boot, system just stopped to boot in 'Windows is starting'. What I did: Into BIOS, reseted all configs to default. Than, reboot and, inside the BIOS (again), reset system to your old configs; Restart Windows and everything should work fine. (I had this idea when I read that this classpnp.sys was a hardware file);
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June 29th, 2010 7:21pm

I'm having some problems with my main HDD. HD Tune pro accuses it of having a very high spin number. I'm working on it;
June 29th, 2010 7:41pm

Hello, A little late but I just wanted to point out that Limbix's solution worked for me. Now, I never created recovery disks. I have a Sony Vaio VGN-NS325J. My computer would just hang on the startup. Then I would get the blue screen of death. It will restart and then give me the option to repair or start normally. I would choose repair. Attempted restore. Initially it would work. But as days went by, it would not restore at all. It would just reboot continously. I tried booting in safe mode and the system would hang at the Classpnp.sys file. I applied the solution provided above to renaming the classpnp.sys with classpnpn.old. Restarted and then the system would hang at the strtup, a brief BLOD would show and the computer would restart. So the bad thing was that I never backed-up my data. So my going in was to try Limbix's solution on pressing Alt+F10. Low and behold, the reccovery screen showed up. I was able to see my C: drive. I backed-up my data. You can backup up to 21 CD/DVDs worth of data in one session. After four DVD worth of backed-up data, the computer restarted. I applied the Alt+F10 key again. This time, I chose restore computer to factory setting. WARNING: This will wipe out everything (formats the drive and restores computer to the same condition when you first purchased it). The computer restored back to the Old Vista Home premium (Originally it was bought with Vista with a free windows 7 upgrade sent later). I did this last night, and I am currently writing this post from the same laptop. Granted that I have to reinstall Windows 7 Upgarde along with the usual Antivirus, MS Office, copy personal files from the backed-up DVDs, etc, etc., I am a happy camper. Basically, I got my laptop back. I am still unsure what caused the problem. A friend of mine said that perhaps a windows update caused the crash. I do not know. A very good lesson has been learned. I will create recovery disks that Sony offers and put them away in case I run into a similar situation in the future. So thank you Limbix for the post. It helped me tremendously. B
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October 25th, 2010 8:02pm

a late reply from me, but is migth be helpfull for people with the same problem as above. I got the classpnp problem but none of the solutions helped for me. A re-install was the only solution i could think of but even in a re-install the system hung during the installation. I begun to think what the problem could be and started to disconnect everything. At last i got to the harddrives and there was the problem, the cable was fine, but the d-drive (not the windows 7 drive) was not. After disconnecting it windows started and made me a very happy man.
April 12th, 2011 2:47pm

Try enter to BIOS and change the disk mode from AHCI to IDE, that works for me. My computer: Acer Aspire 5536 Athlon X2 64 Win7 32bits
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May 21st, 2011 1:14pm

I am having the same issue. I have only had the laptop since January. It is the first time this happened. I updated Windows 7 and then it stopped. Everything I have been told hasn't worked. Trying the BIOS idea and then I'm stumped..
June 13th, 2011 7:00pm

http://social.technet.microsoft.com/Forums/en-SG/w7itprogeneral/thread/773e9de3-554b-4fce-99ca-515784f7a9f9
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October 10th, 2011 5:07am

Had the same problem. Windows 7 startup hung up on classpnp.sys in both normal and safe mode. I don´t know why exactly but resetting the bios via removing the battery fixed it.
October 12th, 2011 10:28pm

Hi, I had the same issue yesterday with my pc after loading fail-safe bios settings (OC gone wrong). After a while I just remembered to change to AHCI in the bios again (I have an SSD)... Solved for me. :)
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October 17th, 2011 12:59am

There's a good chance that you may have a bad memory module or two. I tried a repair disk, safe mode, an Ubuntu Live CD, booting up from a Windows 7 CD. Nothing seemed to work. That is when I decided to make a Memtest86+ bootable CD to test the memory. Sure enough...I discovered two bad memory modules. I threw away those bad modules, and rebooted the machine with the other 4 and everything is fine. To check your memory using Memtest86+ go to http://www.memtest.org/#downiso and burn a CD from the ISO downloads they have there. I tried a million things before I realized it might be a bad memory. Hope this saves you hours of frustration! Enjoy!
November 10th, 2011 12:40am

Will not crash? Blue screen after blue screen ensued, so it is worse than before...Dennis C Kamper
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November 22nd, 2011 7:29am

I got the same problem after updating to Win7 SP1.
December 1st, 2011 8:09am

Same problem. Spent hours benching parts etc. Finally removed wireless card and computer boots just fine. Grrr. Must be an update knocked out wireless card drivers...in our case, anyway. Good luck!
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December 6th, 2011 11:37pm

If it is actually an issue with a corrupted driver, it might be possible to repair it offline, http://mikemstech.blogspot.com/2011/12/how-to-perform-offline-system-integrity.html -- Mike Burr Technology
December 28th, 2011 5:37pm

Worked! Thanks!!!!!!
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January 8th, 2012 2:36pm

Try enter to BIOS and change the disk mode from AHCI to IDE, that works for me. My computer: Acer Aspire 5536 Athlon X2 64 Win7 32bits This also worked for me. i have a sata hdd so never thought of this simple fix. ty
January 15th, 2012 3:15pm

Hi I've just had this with an Acer, System restore etc didnt help but the problem did occur shortly after a windows update I removed a wireless card from the system that wasnt in use and it booted straight up Thanks for the hint above Lee
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January 26th, 2012 12:20pm

Alright I have a dell xps 830 and today I ran Windows Update. My PC no longer boots into windows. I've tried safe mode and it stops at classpnp.sys I have tried system restore, system repair, etc. Next im going to try the disc upgrade.
February 15th, 2012 3:07pm

I though I'd share my solution for anyone else who stubles upon this topic. I had tried all the solutions posted here with no luck, as well as a myriad of other suggested solutions. 1. Boot into Windows Recovery Mode 2. Open command prompt 3. Type: sfc /SCANNOW /OFFBOOTDIR=C:\ /OFFWINDIR=C:\Windows It ran for a few minutes, and said it had successfully repaired some files. I rebooted, and successfully rebooted into Windows. it worked, thanks!!
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March 4th, 2012 5:22am

I have tested this solution. It does crash your computer. it gives a blue screen giving an error for a tenth of a second, then reboots. This Classpnp.sys error is one major pain. There are no definitive solutions to it. My netbook doesn't allow me to try the BIOS solutions mentioned. This solution "can" crash your computer, be warned.
March 7th, 2012 2:23am

hi there, I faced the same poblem too. tried all the sugestions... nothin worked. finaly tapped f8 and selected one of the debugging option.... worked!!! hope this helps..... :)
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March 22nd, 2012 6:25am

Thanks ! It works like a charm ! Feel like a "Genius" !!
April 10th, 2012 1:38pm

Check that your windows directory is actually installed on C:\ I found that my Windows drive had been relabelled as I:\ in Startup Repair mode, even though it is C: when Windows is running.
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June 16th, 2012 10:40pm

A friend of mine had the same problem. Just disconnect all the cable's (from laptop and powersource), take out batteries also. Reconnect, put batteries back inside and hold the powerbutton of laptop down during 30 seconds. Problem should be solved.
June 24th, 2012 8:25am

Right, I battled long and hard witgh this one and found it to be quiet simple if you hold your nerve. 1. Boot from the Windows install DVD or get to Recovery mode via your preferred method choose to start the System Restore mode 2. Choose a point as far back as you can. 3. Restart the machine when prompted and the WAIT!!! I waited almost 45 minutes with a black screen and a hyper active hard drive but hey presto it worked. As a precaution I ran an in-depth stress test to make sure nothing was indeed failing and I was lucky.
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July 3rd, 2012 9:48am

hey guys...never posted on any useful forum before :) very weird, while playing L4D2 coop with the gf,(her on my laptop and me on my rig(laptop gigabyte Q1532 if thats any help.)) game hung and nothing help[ed to exixt it except turning off,had same problems would load into Safe mode,recovery mode and obviously normal. I tried booting into UBUNTU and still nothing :/. i had the same problem with the c:\windows\system32\drivers\classpnp.sys stopping safe mode,just figured i'd leave it for a long time and it logged on.went in deleted L4D2(i dont feel it could have been that as we were 2 missions in)but figured since its the only change/addition i have made to the system and now shes working :) and im talking about the Laptop :) any have insight into this problem i would appreciate an explanation cuz im sooo baffled. and would like to know what caused it im sorry for rambling and im sorry if someone has said this earlier but its 01:10 on sunday morning and i dont want to read through all the replies so not sure if the prob you have is fixed. win 7 64 pro i5 4gb RAM
July 28th, 2012 7:20pm

Running a Toshiba laptop, plugged in a Toshiba external hard drive...epic crash...hangs at classpnp.sys...all of the similar symptoms. Cleaning off the external hard drive and found the "system volume information" folder on the external hard drive. How does that happen. Trying to fix now.
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August 29th, 2012 10:59pm

I have tried all of these and had no luck. I had just replaced a bad MoBo with the same exact one,which i have done with systems before,but now gets stuck on the dreaded classpnp.sys. Ive done all the options in the recovery console,tried unplugging everything,taking the battery out and still no luck. Bought this PC after moving oifff of Craigslist and had worked great for almost a year,but that also means no install disk. I hadnt installed anything new in a while and no new hardware...so for now im stumped.
September 7th, 2012 1:54pm

Issue solved in my case: After having read lots of information over internet, I tried almost everything I was advised to do, tried repairing Windows, overwriting CLASSPNP.sys with more recent and older version, updating system BIOS and running chkdsk, all of that was in vain, the last one I had to take was to reinstall OS, but I had read some posts where people reinstalled OS with no success, so I decided to go for some hardware issue and after some tests I noticed that all the headache was been caused by a damaged memory, just took it out and chose "last known good config" at F8 startup menu, everything is working fine now. Hudson Medeiros MCP 2003/XP
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September 22nd, 2012 12:10pm

I have tried: Safe mode - won't boot changing classphp.sys to classphp.old results in a flash of blue screen of death prior to it rebooting itself Booting from Win 7 recovery CD and running start up fix - = no errors found Restoring to previous date - Failure any date picked Debugging mode - won't boot sfc /scannow - can't perform because a start up fix is in effect checkdisk = no errors found battery out - no effect I have attempted rebooting 30+ times still stalls at classphp.sys file using boot logging or the "starting windows" screen (left overnight, hours, days) Running laptop using an iso file of Linux Xubuntu on CD and laptop is running perfectly, so I don't think its a hardware issue in this case. Have not installed any new hardware in last year. Laptop is a Toshiba Satellite A505--6991 series, Core 2 duo, Win 7 (purchased pre loaded Oct 23 2010). 500GB HD 16GB Ram Wondering if when Win 8 comes out upgrading may fix this so I don't have to reformat my entire hard drive (as above have seen reformatting has resulted in same error) and reinstall everything.... otherwise considering either completely installing the Xubuntu side by side for the time being and or if I have to reformat anyway.. making this a Linux machine completely...
October 11th, 2012 11:30am

I had same issue..boot your PC in safe mode using F8 . It will hang at classpnp.sys. Don't give up,do nothing and after a while your pc should restart itself and you should be able to get in with no issues.
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October 16th, 2012 5:19pm

I had same issue..boot your PC in safe mode using F8 . It will hang at classpnp.sys. Don't give up,do nothing and after a while your pc should restart itself and you should be able to get in with no issues.
October 16th, 2012 5:19pm

AI got the same problem on my HP Z400 workstation. That problem was occur after a BIOS default setting application. My problem was concern the RAID+AHCI setting... I change it for IDE and BINGO! It was solved the problem. Hope this help.
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October 29th, 2012 9:07am

As it turns out, you're all going to find that something different is wrong with each of your computers. Yes it is a hardware issue when CLASSPNP.SYS is the offender. For me, it turned out that I had a hard drive on my secondary Marvell controller that would act up. All I had to do was remove power from that drive and my computer booted fine. Subsequently after booting into Windows I could then turn the key on the pull out drive tray which reapplies power to the drive and I have access to the drive. I am going to check now for driver updates from Marvell that I may have missed. I have an ASUS P8P67 EVO motherboard which actually has Intel and Marvel controllers along with a lot of other stuff that could have gone wrong. I stumbled across the hard drive issue because I didn't want my c: drive to become the f: when I ran a recovery with multiple drives installed. And one reboot before I was to run the recovery, my computer started working again, consistently I can recreate the error by having that drive powered during the boot process and it locks up every time at CLASSPNP.SYS. So start removing hardware one at a time (includes memory modules) untill you get a good boot. Then put all the hardware back in (powered off of course) except the last item you had removed before the computer started acting normal, again. Good Luck, I hope this helps people diagnose their computers and driver issues.
October 31st, 2012 2:37pm

I made an upgrade in my bios and this error started. When I clean my bios, AHCI config was lost, to solve I just change from IDE to AHCI and it worked again!
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November 24th, 2012 5:30pm

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