If the security change with the negative effects had been applied to your computer and for restoring it, you have no back up available, then only you can use this solution. It’s not necessary that all the security settings which were applied to your PC at the time of installing windows would be restored by this solution. Only few settings can be restored.

Steps to restore security settings to default settings:

  1. Below mentioned are the steps to be taken:
  2. Open the command prompt from start menu.
  3. In different operating systems, different commands are there which are mentioned as follows:-

In Windows XP,

Click on Start and then click Run, on the box type cmd and press Enter.

In Windows Vista,

  1. Click on Start and then place the cursor on the search box and type cmd.
  2. Now right click on cmd.exe in the result pane, and then click Run as administrator. You will be prompted to type the password for an administrator account. Click Continue if you are the administrator or type the administrator password. Then, click Continue.

In Windows XP, type the following command, and then press ENTER:
secedit /configure /cfg %windir%\repair\secsetup.inf /db secsetup.sdb /verbose
In Windows Vista, type the following command, and then press ENTER:
secedit /configure /cfg %windir%\inf\defltbase.inf /db defltbase.sdb /verbose

After you enter the above command,you receive a “Task is completed” message and a warning message that something could not be done. This message can be ignored.

Important note:

Before moving ahead, some points need to be noted. They are:

  1. The steps above do not apply to Windows XP Home Edition, or Windows Vista Home Basic and Home Premium editions. For restoring security settings for Home editions, a System Restore or a backup can be used.
  2. You cannot undo the changes without restoring from a backup after security settings are applied.

A complete back up that includes the registry files must be taken if you are not aware or uncertain about this solution of restoring security settings to default settings otherwise the whole data would be lost. Items that are reset include NTFS file system files and folders, the registry, policies, services, permissions, and group membership.

After following the above mentioned steps, when you start your computer or try to switch users, you may no longer see the standard user accounts on the log on screen because they are removed from the user group when you reset windows security settings.

Steps to add users accounts back to User Group

  1. Click Start, and then All Programs. Or click Programs.
  2. Click Accessories, and then click Command Prompt (Windows XP). Or right-click Command Prompt, and then click Run As Administrator (Windows Vista).
  3. In the Command Prompt window, type net users and then press ENTER. A list of user accounts is displayed.
  4. For each accountname listed in the Command Prompt that is missing from the log on or switch user screen, type the following command and then press ENTER:

net localgroup users accountname /add
In this way you can restore your operating system to the original installation default security settings.