Windows 7 (64 bit) bootmanager fails with Status: 0xc0000225

When trying to boot I get the "Starting Windows" but the PC hangs then - no HDD activity, power off is the only course.
In Safe Mode the PC hangs after loading CLASSPNP.SYS

Attempted repair fails with Status: 0xc0000225 "boot selection failed because a required device is inaccessible"

I tried booting off the installation DVD but after loading Windows files it hangs at the "Starting Windows" stage as above.

I am able to boot off a Memtest CD (that shows no errors), also off a general diagnostic (Ultra-X QuickTech Pro) CD that shows no errors in any component.
However, trying to boot off a Knoppix CD hangs leaving a blank screen.  I have restored the HDD from a backup image. The PC comprises mobo, HDD, optical, PSU only and all cables look good and tight.

Having read other posts with the same problem I looked through the BIOS but all seems good there; I did set to default values but problem persists.

Question Info

Last updated May 16, 2020 Views 122,363 Applies to:



I fixed my problem and wish to share the solution. 


By entering safe mode, and selecting the option when each boot step was tracked, I got to the step when the boot process ceased.  It was indeed the anti-virus program. 

I was able to roll back to the last good working OS and re boot. 


I then uninstalled the anitvirus program that caused the conflict.   My system has boot up normally afterwards.  I later installed another anti virus program.   System continued to work well ever since.


Hope this is useful to others.



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