Question Windows can't boot after deleting upper filter in registry

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Mar 30, 2020
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Hello,

My external hard drive wasn't showing up when I plugged it into my laptop. This is because I didn't eject it properly. So I followed some steps online to make the hard drive show up on my laptop:

Step 1. Hit Start, type regedt32 and click OK.
Step 2. Backup your registry by going to file > export.
Step 3. On the left side, go to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E967-E325-11CE-BFC1-08002BE10318}.
Step 4. If you see any upper filter or lower filters at the right side, delete them.

I remember seeing one upper filter so I deleted it. I then plugged my hard drive back in but it still didn't show up. So I restarted and went into BIOS to try and boot from the hard drive. I don't remember making any changes.
I then decided to boot my computer up again but I got an Inaccessible boot device blue screen. I was able to get to the troubleshooting page by hitting Alt and F10. And then I tried pretty much everything from there like safe mode (but it wouldn't boot) and system repair (which didn't work), I didn't have the option to revert back to the last known working version either. I tried even reinstalling Windows while keeping my files but it just brought me back to the same blue screen when it was done.
I have an Acer Aspire E15

I've heard what I could do is to boot from a usb with Windows 10 which I haven't tried yet. But will it keep all of my files?

I also want to make sure my external hard drive is fixed. I tried plugging it into another computer but it still wouldn't show up. If I fix whatever I did in the registry will it show up on another computer? I'm just worried I might lose my files in both my laptop and hard drive
Thanks
 
You decided that a nuclear bomb is the best fix for mice infestation...
YOu have two tasks in front of you:
  • restoring Windows on your laptop. Boot with Windows installation USB, try to repair boot. If you still cant boot, you will have to do clean install, but you will need to copy your files first
  • checking what's wrong with your external drive. That's for another time...
 
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Mar 30, 2020
15
0
10
You decided that a nuclear bomb is the best fix for mice infestation...
YOu have two tasks in front of you:
  • restoring Windows on your laptop. Boot with Windows installation USB, try to repair boot. If you still cant boot, you will have to do clean install, but you will need to copy your files first
  • checking what's wrong with your external drive. That's for another time...
Thanks for your response

So I managed to boot from the usb. Now I'm at this menu - View: https://m.imgur.com/a/EIQgyeO


I already hit the repair option but it eventually brought me back to this screen again. Do I click install then? And how do I copy my files?
 
If you are completely unable to repair Windows to a state, where you can retrieve your files, another option could be, to make a bootable USB with a free Linux distribution of choice, that does not need to be installed, but can be run entirely from the USB thumb drive.

This will allow you to boot into an operating system with a file browser, without installing anything to your harddrive with the broken Windows install, thus avoiding your files to be overwritten, and lets you copy all the important files from there to another drive.

The destination drive for the retrieved files, might need to be formated with ExFAT file system. ExFAT works just fine with Windows.

Once the files are backed up, you can format and reinstall

I have personally had good results with this method, and it shouldn't be much of a problem. You just need a thumb drive, and a working PC for creating the Linux BOOT media, and a destination USB thumb drive or exteral USB HDD

If I remember correctly, I used Knoppix for this method last time I needed it.
 
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Mar 30, 2020
15
0
10
Ok, so can I delete windows off of my usb? And just download Linux on it? My usb is about 29gb. Can you point me to a tutorial or outline how to put Linux on the usb?
Thanks
 
You'll need a working Windows PC to make the bootable Linux thumb drive. It only takes a few minutes, and hopefully you know someone you can borrow a Windows PC from to create the media

I didn't look into potential storage capacity limitations for the Thumb drive, since I always use a 16GB thumb drive for this. You should double check before trying to create the media

Knoppix is what I usually use, but there are several options available - all are free Linux versions under different names. I don't remember them all, but you can look around for a bit, if you want to see if there is a better alternative, than Knoppix, which I uaually use.
Some of the Linux distros are more straight forwarrd to use than others. Knoppix is very similar to what you see in Windows, when it comes to file explorer

What you need

Thumb drive for Knoppix

Thumb drive or USB harddrive as destination drive for the retrieved files. There is a possibility it has to be ExFAT formatted, but I can't remember exactly. It might support NTFS, but if you want to make absolutely sure, format as ExFAT before you begin.

Eventhough the destination drive for the recovered files possibly needs to be ExFAT formatted, it reads the Windows 10 NTFS without issues

Your files will show up under the folders and file names you are used to, but navigation in file exploerer migt look a bit different, since it shows some numbers and letters that are not displayed in WIndows

Unless you are 100% sure you have backed up your important files, do not reinstall or format the current harddisk with the broken Windows install.

Before proceeding with Windows re-install, make sure on a different PC; that the recovered files are complete and undamaged.

After all the important files are secure, your can reformat your laptop's harddrive, and clean install Windows 10

In the future, remember to make backups frequently, before everything goes badly wrong like in this situation. With everything backed up,you'd have little reason to worry when Windows suddenly doesn't work

EDIT:
This is just a suggestion in case you can't acces the files by repairing your current Windows installation. But it is very safe at the same time, since no files are written to your your current harddrive
 
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Colif

Win 11 Master
Moderator
choose troubleshoot
choose advanced
choose command prompt
type notepad and press enter
in notepad, select file>open
Use file explorer to copy any files you need to save to USB or hdd

use that to copy info off PC or move to another drive (if you have one)

once you do that, reinstall win 10
follow this guide: https://forums.tomshardware.com/faq/how-to-do-a-clean-installation-of-windows-10.3170366/

and if you go into registry again, back it up first. Or just don't go in, as I hardly ever advise people to go into it.
 
Mar 30, 2020
15
0
10
For what it's worth I do remember exporting a backup of the registry before I deleted the upper filter if that changes anything.

I can see my files in notepad which is good. Thanks. I should back them up before doing the regedit thing in cmd, although I don't know how to repair the damage from there
 

Colif

Win 11 Master
Moderator
To restore the registry using a previously created .reg file on a Windows 8 or 8.10 system, follow these steps:

Open the Registry Editor: type regedit at the search box and click on the regedit item when it appears in the search results list.
At File, click the Import option
At the Import Registry File screen, browse and select the backup file you want to restore
Click Open
Once the process is complete, restart your computer and log back in on your Windows 10 computer

https://neosmart.net/wiki/backup-restore-registry/#Back_up_and_restore_the_registry_in_Windows10

try that in cmd

another fix that could work is a system restore as it includes registry so if you have a date prior to the changes, you can roll back to it.
 
For what it's worth I do remember exporting a backup of the registry before I deleted the upper filter if that changes anything.

I can see my files in notepad which is good. Thanks. I should back them up before doing the regedit thing in cmd, although I don't know how to repair the damage from there
If this is the case, simply open regedit, click import and it will show the backup you made, click on the reg save file and it will restore your registry..
 
Mar 30, 2020
15
0
10
Ok, so I found a similar solution to what you're saying:

"run regedit,
Left click on HKLM (left side of Registry Editor) and load System hive, located in F:\Windows\System32\config\SYSTEM (assuming F: is the drive letter of windows partition from connected drive)
manually add deleted entries:
LowerFilters EhStorClass
UpperFilters partmgr
Unload the hive."

Do I have to plug in my external hard drive I was trying to fix? How exactly do I go about doing this? I just don't want to mess it up any more than I have is all
 
Ok, so I found a similar solution to what you're saying:

"run regedit,
Left click on HKLM (left side of Registry Editor) and load System hive, located in F:\Windows\System32\config\SYSTEM (assuming F: is the drive letter of windows partition from connected drive)
manually add deleted entries:
LowerFilters EhStorClass
UpperFilters partmgr
Unload the hive."

Do I have to plug in my external hard drive I was trying to fix? How exactly do I go about doing this? I just don't want to mess it up any more than I have is all
My fix is a little more detailed, run regedit.

Go to the location of the upper filter key you deleted. Click Edit-> New->Multi-String Value. Change the name to UpperFilters, double click on the name you just changed and add to the data partmgr (press enter) and add EPMVolFl so EMPVoIFI is under partmgr than click Okay.

If you also deleted the lower filter, do the same but name LowerFilters and add the data EhStorClass
 
Now that the registry has apparently been repaired. return to the Recovery environment (three failed boots should bring it up); 1st go to the command prompt and verify the filters you deleted are in place; if they are #2 see if the startup troubleshooter will work. If not,#3 boot up the windows media you have, choose repair, and again see if the startup troubleshooter will fix the problem.
 
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