File security permissions messed up by chkdsk


Well-Known Member
Some days back my chkdsk started running after a reboot.
Everything was fine until it found some errors and i got this line...

Replacing invalid security id with default security id for file 97.
Replacing invalid security id with default security id for file 98.
Replacing invalid security id with default security id for file 99.

Some 10,000 or so files later it ended but my PC didn't restart automatically.
I pressed the reset button and after that all was hell.

For e.g.

1) My host file entries were not readable by any applications like wamp or firefox or chrome or etc.

2) I could not start some programs like MATLAB because its file also got corrupted.

3) Avira Antivirus does not update because it says Scheduler (sched.exe) has not been started even after starting it from services.msc.

I googled this problem and came to know that my account has been removed from the permissions list of the files (as seen when i saw the properties of the hosts file).

Please help me to include my account in the permission list because after adding it manually gives me a permission denied error.

Thank you to read so patiently...

P.S. : I searched eventvwr.msc but it does not show up chkdsk logs...


Excellent Member
Microsoft Community Contributor
Have you run any anti-virus since this happened? Many folks here like Malwarebytes if you are able to run it. You might look for a version you can run from a flash drive.

Do you have an Windows 7 Install DVD or a repair CD you can boot to?

I suppose you do not have the ability to add another user as admin, or activate the built-in admin account?

It seems a couple of months ago we had some folks that had lost the admin privileges in their account. I will do some research.


Well-Known Member
The thing is that i have not lost my admin privileges entirely.
It is just that for those files whose security descriptors have been messed by chkdsk I am not able to modify.

I haven't had much problems with my PC except the above mentioned, but hosts file is a problem.

Also, FYI I tried to add my user and 'Authenticated Users' in the Security properties of the hosts file. It got added but after clicking OK i got permission denied.
I don't know how to interpret this problem but see if you can understand from this description.

One more thing, I am sure it is definitely not a virus or malware problem so no point in installing stuff which is not required.

I have Win 7 DVD but I don't have restore points from which I can go back to my previous config and I don't wanna format too. That would be my last option.


Excellent Member
Microsoft Community Contributor
If you are messing with the Hosts file, then you are doing something a little unusual for Windows 7. The file is protected and you have to alter its security to do so. Not like XP.

If you can run an Repair Install, that may fix your problems, and it sounds like you have the authority to do that.

But you still need to find out why your security settings were changed.

Edit: You could also try opening an administrative command prompt and type the following command and enter after.

SFC /scannow

Let it finish and check if any files could not be repaired. Don't know if it will pick up security changes on the files, but it would not hurt.

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Well-Known Member
I used to meddle with hosts to block some sites at home. Until now it was working fine until chkdsk messed up.

I tried your solution but it says it didn't find any integrity violations so that method is out of the window.

I think you didn't understand my situation.

According to me, when there is no user account present in a PC (that's a hypothetical situation but is just after installing windows before you create an account), only 'System' and 'Smit-PC\Administrators' have permission to system files. When you create an a/c and if it is an admin, it automatically show up in the Security properties of system files.

e.g. If I create an admin account Smit, then u'll find the user Smit-PC\Smit automatically added in the list.

What has happened in my case, chkdsk has put the default settings in all those so-called-corrupted-files. Hence, my username is not there in the list (only System and Smit-PC\Administrators are allowed permissions) and I cannot do it manually to each and every file and moreover I am not authorized to change the permissions because my account is already out of the list.

This is the most I could explain an I hope you can help me out without formatting the OS and making a new user a/c because I have lots of settings done in this a/c.

I know I am asking a lot but I think it may be possible with people like you...:)


Excellent Member
Microsoft Community Contributor
Maybe I do not understand. A picture might help, but for now, if I look at the hosts file properties, security, it shows:

Administrators (Computer\Administrators)
Users (Computer\Users)

There is not an individual entry for different users. But you are saying you do not show the Users entry?

Or, if you look at Computer Management, Local Users and Groups, you are not listed in the Users Folder?

I will look at items related to user profiles. Maybe yours has a problem. And I am not suggesting you add a new user and then switch over, just use it to reset your user account.

But I have never seen Chkdsk do what you say. That is why it seems a virus or some other system alteration is causing it.


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Well-Known Member
I tried a fix of my own.

I created an admin account and added this line in the Properties of hosts
Users (Computer\Users)

Then I logged into my original account and confirmed that the settings were still there.
Opened Mozilla to check and then everything started working properly.

My account still has some minor problems but this makeshift arrangement is enough for me.
Of course this has to be done to all the files which face problem, i think there is now way out.

I need 2 days to format and restore my PC and its settings back to original which is simply tiring.

Btw mine is Windows 7 Home Premium, so gpedit is missing frm my PC and also there is no section of 'Local Users and Groups' in Computer Management.

Anyways Thnx a lot for all your help...:)

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