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Registry Key Permissions (Cannot open Windows: error while opening key)

Last Modified: 2012-05-11
I just removed several viruses from my customers computer (Windows XP SP3).  I am now trying to uninstall AVG 9 so we can install AVG 2011.  During the uninstall process, it fails stating it does not have access to the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows.

When navigating to the key manually, I get the following error.  Cannot open Windows: error while opening key)

I have tried changing the permissions and owner but get the following error.  Unable to set new owner on Windows.  Access is denied.

Any ideas how i can fix this?
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I presume you're using regedit?  What does it show when you right click that key and select permissions?  It should list the local admin group with full control and you are hopefully logging in as a member of that group?
Most Valuable Expert 2011
Top Expert 2011

In the registry, go to.....

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

Rt Click>Permissions>Advanced, and make sure that Administrators has Full Control, and select the botom checkbox "Replace all child permissions with inheritable permissions from this object"....

Then see if you can access the Windows subkey......

You really dont need to take ownership of the key.
Sudeep SharmaTechnical Designer

John advice would work however below utilities would still help you in uninstalling the AVG if it fails from Add/Remove program
AVG Remover

AVG Remover eliminates all the parts of your AVG installation from your computer, including registry items, installation files, user files, etc. AVG Remover is the last option to be used in case the AVG uninstall / repair installation process has failed repeatedly.

AVG Remover(32bit) 2011

AVG Remover(64bit) 2011

After running the removers:

More downloads at:

Below is one more application remover for AVG, this from Sun Belt Software who have created Viper and GFI.



I hope that would help

Most Valuable Expert 2011
Top Expert 2011
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Top Expert 2007

For registry editing:
Try using the "At /interactive regedit.exe" command.
At DOS window. Type in below example:(change "12:00" to what time you want permission, e.g. 1 minute ahead in real time) it works.

at 12:00 /interactive regedit.exe

From the above example:
This means that at 12:00 the registry will have SYSTEM privileges! - you should be able to do anything at this time.


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