SSD/Motherboard/GPU Issues - BSoD: Driver PNP Watchdog + Inaccessible Boot Device

Jul 26, 2018
I've been using my PC for a couple years now and a week ago my PC started freezing up and lagging very bad shortly after booting up (I updated Windows the night before). It was so bad that I could not open the start menu so I turned off my PC manually. After turning it back on, it got stuck on the motherboard logo screen (where you enter BIOS etc.), Asrock for me. After maybe 3-5 minutes I saw the Windows spinning-dots loading screen. I was stuck there for 10+ minutes before I was finally sent to my lock screen. I pressed a key to enter the password prompt and a couple minutes later it popped up. Pressing keys would sometimes result in them showing up but before I could ever get my password entered the prompt would close due to inactivity. After this I plugged in a Windows recovery USB and booted from that. The startup repair didn't work. After some more restarts my PC stopped sending me to the lock screen. Windows would give me the loading screen and the caption, "Preparing Automatic Repair." Then I'd get a BSoD with stop code "DRIVER PNP WATCHDOG" or "INACCESSIBLE BOOT DEVICE." I went into the BIOS and saw that no boot device was being detected (aside from the USB). I unplugged my SSD and plugged it into a different sata port and went into the BIOS again to see that it was being seen now. However, booting from it still resulted in the same BSoD. Going back into the BIOS I saw that the SSD was no longer being seen again. Just recently my monitor stopped working as well. The blinking blue light indicated that it was recieving power but was not recieving a signal from the GPU. I've tried two other HDMI cables and another monitor with no luck. My GPU only has DVI and HDMI capatability. I have not yet tried using a DVI cable so perhaps the problem is just limited to the HDMI port on the GPU? I'm assuming both the GPU and SSD problems are not coincidence and that perhaps there is a problem with the motherboard. It would also explain the lag on the motherboard screen before my PC even attempted to access the SSD. The cause of all these problems is most likely not malware although I guess it's always a possibility. From the miniscule amount of research I've done I believe this problem is unique to SSDs and possibly a driver error with Windows which seems likely since my PC hasn't worked since I updated Windows. Even if you can't solve any of the problems any knowledge that can help me better understand the hardware and how they work would be greatly appreciated. Thanks in advance.


Apr 13, 2018
I think you have software problems arising from a windows update. This is not unique.
I assume you only have one ssd and no back up drive. That's not unique either and should be remedied. Now is as good a time as any.
Go now and buy a cheap ssd, 500GB is a nice size, disconnect the current drive, install windows on the new drive, then attach the current drive , and transfer your personal files from the old drive to the new one, make sure the new one works well, then clone the new drive to the old drive and keep the clone current.
Jul 25, 2018
Sometimes it is just an issue that cannot be solved by trying to use software.
You mentioned that the window boot tools on your USB drive no longer let you do anything.
But you did not mention if you tried the USB since the monitor issues.
I would do the following.
Unplug the PC. Remove the ssd and GPU. Remove the memory and remove the sata cables. Then remove the Main power distribution cable from the PSU to the motherboard and then go drink a coffee.
Leaving everything disconnected gives you the opportunity to ensure all connections are secure and in order when reconnecting them.
Leaving the motherboard without power for 10 minutes ensures the board is drained and will restart to MB defaults.
You also said a couple of years ?? The small battery on your motherboard that keeps the timings and bios should last anywhere from 5 to 7 years without issues. However it is a common problem that if the battery is dying it can throw up all manner of errors. Disks not found booting problems etc.
Also SSD's like AHCI set in the bios not IDE.
Once you have everything put back together try the USB again. See if you have a system restore point from before the update.
If you do not but the system boots with the USB you will need to place another drive into the PC and remove the SSD.
With a new drive do a clean install of windows and then do the updates etc.
If all goes well then shutdown placed the SSD back into the system and then software to move your personal data off the SSD onto the new drive.
I would not clone it as anything not 100% including the broken update would be cloned.
If you can get your personal data from the SSD onto the new drive and everything is as it should be you can then format your present SSD and do testing to see if the SSD is healthy and working properly. Some of the issues you describe have nothing to do with a dying or corrupt SSD.
So in my humble opinion there is more going on than simply a bad update wrecking your OS causing slowdowns and other odd glitches.