A computer running supposedly genuine and legitimate Microsoft Windows XP may start to fail the Windows Genuine Advantage (WGA) validation process, or is simply reported as being non-genuine, or not genuine by the WGA ActiveX validator. The problem may be caused by an incorrect Data.dat file or by a corrupted Data.dat file located in the %AllUsersProfile%\Application Data\Windows Genuine Advantage\data folder.

To resolve and fix the WGA failed or wrong validation issue, delete and remove the Data.dat file from the Windows XP-based client computer, and the Data.dat file will be updated correctly during the next validation. Follow the steps below to update the WGA Data.data file manually:

  1. Log on to the computer that is experiencing the problem by using an account that has administrator credentials.
  2. Delete the Data.dat file from the %AllUsersProfile%\Application Data\Windows Genuine Advantage\data folder.

    By default, the %AllUsersProfile% folder is the C:\Documents and Settings\All Users folder.

  3. Visit the following Microsoft Web site to confirm that the computer is reported as genuine:


  4. Click Start, click Run, type wgatray.exe /b, and then click OK.

    Note that wgatray.exe will not be found is the Windows Genuine Advantage Notifications is not yet installed. If the executable is not found, just skip to next step.

  5. Restart the computer.

In addition, MGADiag.exe (Genuine Advantage Diagnostics Tool) can also used to automatically update the WGA Data.data on the computer. However, this method may not work if there is permissions set on Data.dat which prevents access.

  1. Download Microsoft Genuine Advantage Diagnostics Tools: MGADiag.exe
  2. When you are prompted, click Run to run the Microsoft Genuine Advantage Diagnostic Tool.
  3. Click Continue.
  4. On the Windows tab, click Resolve.