How to Restore administrator Permissions ?

[CLONEOPS]

Hello,

I accidentally deleted the permissions of the administrator and system in the "security" tab of the properties of the disk c: / windows vista.
The only remaining group is used (with permission to read, execute, and display).

I would like to restore the original settings. So I selected "edit", "add", I joined the group "administrator" and I selected "Full Control". But when I want to apply, it displays an error: it denies access to c: /.

I think I do not have access to change these permissions because I deleted the authorization before! But how to restore administrator permissions in this case?

Thank you very much

[SreeKanth]

Hello,

That is the kind of accident should be avoided!

You might be a chance to get the rights on your account in applying this procedure:

1. You restart in Safe Mode (you tap the F8 key at restart and you choose Safe Mode)
   
2. In a Command Prompt (All Programs -> Accessories -> Command Prompt), you tapes or copy paste this command:
   
3. net localgroup Administrators UserName "/ add
   
4. UserName is the name of the account for which you have lost administrative rights.
5. Of course, you replaced by the exact name of your account and you respect the space well.
   
6. Example, if your account is called Thomas, the command will be:
   
7. net localgroup Administrators "UserName " / add
   
8. You Press Enter.
   
9. You close the Command Prompt and restart you in normal mode.

Tell us if you could recover your rights.

[CLONEOPS]

Hello,

Thank you for your reply. Unfortunately it did not work when I typed the command, he displayed "the specified account name is already a member of the group". Then I closed the prompt and restart in normal mode, I went to see in security, but there was no change. It was still impossible to add a user and give permissions.

[SreeKanth]

Hi

Still in Safe Mode, try a System Restore to an earlier date.
You choose a date prior to your accident and hope that it will be able to re-assign the rights to C.

If this does not try to create another session administrator and see if this session you have the rights to C.