How to correct common User32.dll file errors

What is the User32.dll file?

Windows stores instructions for graphical elements such as dialog boxes and windows in the User32.dll file. The User32.dll file is necessary to the operation of Windows. If this file is damaged, deleted, or removed, the system will no longer work correctly. If a program or a service accesses User32.dll incorrectly, the program or the service will not work correctly.


User32.dll errors are typically corrected by repairing the User32.dll file or by reinstalling the program, the hardware component, or the driver that is causing the error. If these procedures do not correct the User32.dll error, you can restore your computer to a condition before the error appeared by using the Windows System Restore feature.

Note If you cannot start Windows because of a User32.dll error, see the "Start your computer in safe mode and use System Restore" section.

Microsoft Windows Update Web site

You can also update Windows by using the Windows Update Web site. To do this, visit the following Microsoft Windows Update Web site:

http://windowsupdate.microsoft.comNote You can also receive updates for Windows, Microsoft Office and other Microsoft applications in Microsoft Update. Microsoft Update brings you all the features and benefits of Windows Update plus downloads for other Microsoft applications that include Office. To use Microsoft Update, visit the following Microsoft Web site:

http://update.microsoft.com/microsoftupdate

Turn on Automatic Updates

To have Windows install important updates as they become available, turn on automatic updating. To turn on Automatic Updates in Windows, follow these steps:

• In Windows Vista:

  1. Click Start, click All Programs, and then click Windows Update.

  2. In the navigation pane, click Change settings.

  3. Select the option that you want.

  4. Under Recommended updates, click to select the Include recommended updates when downloading, installing, or notifying me about updates check box, and then click OK. If you are prompted for an administrator password or for confirmation, type the password, or provide confirmation.

• For more information about how to schedule automatic updates in Windows Server 2003, in Windows XP, and in Windows 2000, click the following article number to view the article in the Microsoft Knowledge Base:
  
  

  327838 How to schedule automatic updates in Windows Server 2003, in Windows XP, and in Windows 2000
  
  

Manually update drivers

It is best to let Windows automatically install drivers for your hardware. You should avoid manually updating a driver unless Windows is unable to find a driver for one of your devices, and you were able to obtain a driver some other way. Or, you may have to manually update a driver if technical support personnel ask you to install drivers from a disc or from the device manufacturer's Web site. If you decide to manually update a driver, follow these steps:

1. Click Start, and then click Run.

2. Copy and paste (or type) the following command in the Run box, and press ENTER:
   
   devmgmt.msc

3. If you are prompted for an administrator password or for confirmation, type the password, or provide confirmation.

4. In Device Manager, locate the device that you want to update, and then double-click the device name.

5. Click the Driver tab, click Update Driver, and then follow the instructions.

Start your computer in safe mode, and use System Restore

If you cannot start System Restore, you can use Windows safe mode to start System Restore. For information about how to start Windows Vista in safe mode and to use System Restore, visit the following Microsoft Web site:

http://windowshelp.microsoft.com/Windows/en-US/Help/6b969e00-d4ec-4d3a-bffe-b96107e3bda91033.mspxFor more information about how to start Windows XP in safe mode and to use System Restore, click the following article number to view the article in the Microsoft Knowledge Base:

304449 How to start the System Restore tool at a command prompt in Windows XP

Use the Backup or Restore Wizard in Windows Server 2003 and in Windows 2000 to restore your computer to a time before you received the User32.dll error.For more information about how to restore Windows Server 2003 and Windows 2000, click the following article numbers to view the articles in the Microsoft Knowledge Base:

325375 How to troubleshoot startup problems in Windows Server 2003

315396 How to troubleshoot startup problems in Windows 2000

Important We recommend that you run Windows Update after you perform a system restore. For more information, see Method 1. We also recommend that you update your antivirus software after you have run Windows Update. For more information about antivirus software supported by Microsoft, click the following article number to view the article in the Microsoft Knowledge Base:

49500 List of antivirus software vendors

Method 1: Use Recovery Console to restore the User32.dll file

Some User32.dll errors can be fixed by restoring the original User32.dll file from your Windows CD. Restoring the User32.dll file replaces the copy of User32.dll on your computer by using the original copy of User32.dll that is contained on your Windows CD.

You can use this method if you are running one of the following Windows operating systems:

• Windows XP

• Windows Server 2003

• Windows 2000

For more information about how to restore files in Windows Vista, click the following article number to view the article in the Microsoft Knowledge Base:

936212 How to repair the operating system and how to restore the operating system configuration to an earlier point in time in Windows Vista

Note You may find it easier to follow the steps if you print this article first.

Before you perform this procedure you should have the Windows installation CD.

1. Insert the Windows XP CD into your computer, and then restart the computer.

2. If you are asked whether you want to start the computer from the CD drive, click Yes.

3. When the "Welcome to Setup" screen appears, press R to start the Recovery Console.

4. When you are asked to type the Administrator password, type the Administrator password. If the administrator password is blank, just press ENTER.

5. At the command prompt, type the following command:

   cd %systemroot%\system32

6. First, rename the damaged or corrupted file so that it is not deleted when you copy the original file. To do this, type the following command:

   ren USER32.DLL USER32.BAK

7. Next, restore the original User32.dll file from the Windows CD to your computer. To do this, type the following command:

   expand [CD drive letter]:\i386\USER32.DLL %systemroot%\system32 /YNote In this command, replace [CD drive letter] with the letter of your CD drive, such as D.

8. To exit the Recovery Console and to restart the computer, type exit at the command prompt, and then press ENTER.

Important We recommend that you run Windows Update after you restore a file by using Recovery Console. For more information, see the "Method 1: Use Windows Update to obtain any fixes that are related to User32.dll" section. We also recommend that you update your antivirus software after you have run Windows Update. For more information about antivirus software that Microsoft supports, click the following article number to view the article in the Microsoft Knowledge Base:

49500 List of antivirus software vendors

For more information about the Recovery Console, click the following article numbers to view the articles in the Microsoft Knowledge Base:

314058 Description of the Windows XP Recovery Console

326215 How to use the Recovery Console on a Windows Server 2003-based computer that does not start

229716 Description of the Windows 2000 Recovery Console

Method 2: Use the System File Checker tool to repair User32.dll

System File Checker lets you scan all protected files to verify their versions. If System File Checker discovers that a protected file has been overwritten, it retrieves the correct version of the file from the cache folder (%Systemroot%\System32\Dllcache) or from the Windows installation source files, and then replaces the incorrect file. You must be logged on as an administrator or as a member of the Administrators group to run System File Checker. For more information about how to use the System File Checker tool, click the following article numbers to view the articles in the Microsoft Knowledge Base:

310747 Description of Windows XP and Windows Server 2003 System File Checker (Sfc.exe)

936212 How to repair the operating system and how to restore the operating system configuration to an earlier point in time in Windows Vista