Last week when I installed CCleaner on my system, it also installed Avast antivirus software stealthily, in the background. After I uninstalled Avast, a registry key named AVAST Software still remained in the registry, but it couldn’t be opened. When the AVAST Software branch was selected, it threw the following error:
Error Opening Key AVAST Software cannot be opened. An error is preventing this key from being opened. Details: The system cannot find the file specified.
When I opened the Properties of the AVAST Software key, the Security tab was blank, showing the message: The requested security information is either unavailable or can’t be displayed.
I tried running Sysinternals RegDelNull to nuke the keys, but that didn’t help.
The same error can occur for AVG antivirus users.
Error Opening Key AVG cannot be opened. An error is preventing this key from being opened. Details: The system cannot find the file specified.
Registry Reparse Point
Later I realized that the
HKEY_LOCAL_MACHINE\Software\AVAST Software is a reparse point or registry link that links to the following key on Windows 64-bit systems:
But, since the Avast uninstaller had wiped out the above key, the reparse point still remains but is orphaned.
On Windows 32-bit systems, the reparse point and the target key paths are reversed.
Fix: Can’t delete Avast Software Registry Key
Method 1: Create AVAST Software key under WOW6432Node manually
To successfully remove the
AVAST Software reparse point, first, manually create the missing target key. Follow these steps:
- Start the Registry Editor (
- Create the
AVAST Softwarekey under the
Alternately, run the following command from an admin Command Prompt window to create the key manually on a Windows 64-bit system:
reg add "HKLM\Software\AVAST Software" /reg:32
- Then, go to the following key in the Registry Editor and delete it:
This deletes the linked key as well as the reparse point in one go.
Important Note: If, the
WOW6432Node\AVAST Software key is the reparse point itself (32bit vs 64-bit Windows) which can’t be opened, and points to the key
Software\AVAST Software, then you’ll need to create the target key (
HKLM\Software\AVAST Software) key manually before deleting the reparse point.
Method 2: Use AvRegLink.exe from Avast Software
Avast software has a tool named
AvRegLink.exe which can create, query or delete reparse points in the registry. This tool can be downloaded from the following URL:
Once downloaded, open admin Command Prompt and run the following command:
AvRegLink.exe delete "SOFTWARE\AVAST Software"
WOW6432Node\AVAST Software key is the reparse point itself (32bit vs 64-bit Windows), which points to the key
Software\AVAST Software, then you’ll need to run this command instead:
AvRegLink.exe delete "SOFTWARE\WOW6432Node\AVAST Software"
Before deleting the reparse point, if you want to query the reparse point to know where it’s pointing to, use this command-line:
AvRegLink.exe query "SOFTWARE\AVAST Software" AvRegLink.exe query "SOFTWARE\WOW6432Node\AVAST Software"
To create a reparse point manually, use this command-line syntax:
AvRegLink.exe create LinkKey TargetKey
Method 3: Using the regln tool
Usage: regln [-v] <link_key> <target_key> regln -d <link_key> <link_key> is the new registry link key <target_key> is an existing registry key being linked to -v = volatile, exist in memory only -d = delete link
regln -d "HKLM\Software\WOW6432Node\AVAST Software" -and- regln -d "HKLM\Software\AVAST Software"
This deletes the AVAST Software registry key and also the link from the
HKEY_LOCAL_MACHINE\WOW6432Node\Software registry locations.