Removed a wrong registry key. How do I get it back?

Cryozeal · 12 Oct 2015

Hi, I'm still new to this forum. This is the first time I post. I have been reading stuff from here for a while. If I post at a wrong place, please let me know.

Yesterday I was trying to fix an issue with network adapter on my Win10 PC. I followed a guide I found on the net suggesting that I should try to remove "LowerFilter" key from which can be found under
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}

However, I believe that I accidentally deleted LowerFilter from a wrong place, under
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}

Is there anyway I can retrieve or recreate this? Anyone know the value of this LowerFilter?

Thank you in advance.

john262 · 12 Oct 2015

You could probably try using System Restore. Hopefully your system has a restore point dated before this happened.

Kanata · 12 Oct 2015

Each of those class values corresponds to a piece of hardware. By removing the LowerFilters or UpperFilters key, it may just stop that particular device working and you would likely need to at least reboot the computer or at most reinstall the software that corresponds to that piece of hardware to restore these keys. Next time back up the registry before altering it.

Ztruker · 12 Oct 2015

System Restore is disabled by default in Windows 10, at least on every Windows 10 system I've setup so far, which is 20 or so.

To enable it,

Right click on This PC and select Properties.
Click Advanced system settings at left.
Click the System protection tab.
Select the boot drive then click the Configure button.
Select Turn on system protection and click OK.
Click Create to make your first restore point.
Others should be created weekly or as needed.

Won't help with your current problem if it's disabled but can help with future problems.

Ztruker · 12 Oct 2015

I just looked at mine and this is what it's set to:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e965-e325-11ce-bfc1-08002be10318}]

Removed a wrong registry key. How do I get it back?-lowfilt.jpg

topgundcp · 12 Oct 2015

Windows normally keep a backup copy of the registry under:
C:\Windows\System32\config\RegBack
namely: DEFAULT, SAM, SECURITY, SOFTWARE,SYSTEM

So if you boot up from the recovery disk and look at the date of these files. If it's earlier than when you deleted the entry then just copy them back to:C:\Windows\System32\config

NOTE: You need to turn on: Show hidden files/folders options to be able to see these folders.

simrick · 14 Oct 2015

Just curious....Aren't the upper and lower filters usually referring to CD/DVD drives? Why would you mess with them for a network adapter issue?