OS not loading, Safe Mode won't boot past classpnp.sys

[thebladeroden]

I replaced my Intel Q6600+DP35DP mobo with an i5-4690K and Asus Z97 K. I get a "missing operating system" message. When I boot up with a Windows 7 64 bit installation USB and then Repair Your Computer, it does find the OS on the hard drive still.

I tried following this guide for repairing the boot manager
How to Fix Windows 7 When It Fails to Boot

but I didn't get anywhere, until I tried this part

*Some users also find simply deleting the boot folder and retrying the above steps effective at resolving boot issues, but it is not recommended.

Now instead of "Missing Operating System" I get the "Windows Error Recovery. Windows failed to start. A recent hardware or software change might be the cause" then it recommends I do the startup with the installation disc and repair my computer.

If I instead Start Windows Normally, it displays a few seconds of the startup animation then auto restarts.

If I chose Safe Mode, it shows Loading Windows Files until it gets to windows\system32\drivers\classpnp.sys, pauses for a second then restarts.

If I boot up with the installation USB again, and selecting my Windows installation it will tell me "You computer was unable to start; StartUp Repair is checking you system for problems" and start searching for problems for a few minutes, and then attempting repairs for a few minutes, and then it will give me "startup repair cannot repair this computer automatically"

And then it has these details.

Event Name: StartupRepairOffline
Signatures:
0.0.0.0
6.1.7600.16385
unknown
21200273
ExternalMedia
17
NoRootCause
OS Version: 6.1.7601.2.1.0.256.1
Locale ID: 1033

After that if I try to repair startup from the next screen it will give me "startup repair could not detect a problem" *shrug*

I've tried both SFC and DSKCHK but neither of them have reported any problems.

 

[matts6887]

Well if im not mistaken; anytime you switch to a new motherboard; it is generally a good idea to do a completely fresh install of the windows operating system because the drivers for the motherboard will be different etc. But also; before doing a fresh install of windows; try following the steps in the following link and see if that doesnt help ya out. If not; post back and we can go from there.

http://www.sevenforums.com/tutorials/219533-troubleshooting-windows-7-failure-boot.html

 

[bigmck]

I agree with Matts6887 that a http://www.sevenforums.com/tutorials/1649-clean-install-windows-7-a.html is needed to get things going for you. You will need the Product Key to activate the Win 7 after it is installed. Since you have a Custom Build, I assume you have a Win 7 disk from your first installation. The Product Key will be on the DVD. == If your Win 7 DVD is a OEM copy, you are not allowed to use it again when a motherboard has been changed. OEM copies are tied to the motherboard and are not transferable. A new copy will have to be purchased.