How to repair the operating system and how to restore the operating system configuration to an earlier point in time in Windows Vista

The System File Checker tool

To determine whether the issue that you are experiencing is caused by one or more system files that are used by Windows Vista, run the System File Checker tool. The System File Checker tool scans system files and replaces incorrect versions of the system files by using the correct versions.

To run the System File Checker tool, follow these steps:

1. Click Start , and then type cmd in the Start Search box.
2. Right-click cmd in the Programs list, and then click Run as administrator.
   
    If you are prompted for an administrator password or confirmation, type your password or click Continue
3. At the command prompt, the following line, and then press ENTER:
   sfc /scannow

When the scan is complete, test to see whether the issue that you are experiencing is resolved. If the issue that you are experiencing is not resolved, use the procedure that is described in the "The System Restore tool" section.

The System Restore tool

Other troubleshooting methods, such as using the System File Checker tool, may not resolve the issue. If they do not resolve the issue, and the issue that you are experiencing started occurring recently, you can use the System Restore tool. By using this tool, you can restore the computer to an earlier point in time.

Using the System Restore tool may not necessarily help you determine the issue. The System Restore tool uses restore points to return system files and settings to an earlier point in time. You can use it to restore the operating system to a point in time in which you did not experience the issue. When you use System Restore to restore the computer to a previous state, programs and updates that you installed are removed.

To restore the operating system to an earlier point in time, follow these steps:

1. Click Start , type system restore in the Start Search box, and then click System Restore in the Programs list.
   
    If you are prompted for an administrator password or confirmation, type your password or click Continue.
2. In the System Restore dialog box, click Choose a different restore point, and then click Next.
3. In the list of restore points, click a restore point that was created before you began to experience the issue, and then click Next.
4. Click Finish.
   
   The computer restarts, and the system files and settings are returned to the state that they were in at the time that the restore point was created.