These instructions to disable or uninstall the pilot version of Microsoft Windows Genuine Advantage Notifications are from the horse’s mouth i.e. Microsoft itself. 
Note: If you are looking to cleanly remove Windows Genuine Advantage Final version then look here.
Disable WGA Notifications
| 1. | 
Log on to the computer by using an account that has administrative permissions. | 
| 2. | 
Make sure that the WGA Notifications version that exists on the computer is a pilot version. The version format for the pilot version is 1.5.0532.x. In this case, you can uninstall versions 527-532 only. For example, you can uninstall versions that range from 1.5.0527.0 to 1.5.0532.2.  To find the WGA Notifications version, follow these steps: 
| a.  | 
Click Start, and then click Control Panel. | 
 
| b.  | 
Double-click Add or Remove Programs, locate and then click Windows XP - Software, then click Windows Genuine Advantage Notifications, and then click Click here for support information. | 
 
| c.  | 
In the Support Info dialog box, verify the version number, and then click Close. | 
 
 
 | 
| 3. | 
Rename the following files by changing the extension to .old: 
| » | 
Rename %Windir%\system32\WgaLogon.dll to %Windir%\system32\WgaLogon.old | 
 
| » | 
Rename %Windir%\system32\WgaTray.exe to %Windir%\system32\WgaTray.old | 
 
 
 | 
| 4. | 
Restart the computer. | 
Manually uninstall WGA Notifications
| 1. | 
Log on to the computer by using an account that has administrative permissions. | 
| 2. | 
Make sure that the WGA Notifications version that exists on the computer is a pilot version. The version format for the pilot version is 1.5.0532.x. In this case, you can uninstall versions 527-532 only. For example, you can uninstall versions that range from 1.5.0527.0 to 1.5.0532.2. To find the WGA Notifications version, follow these steps: 
| a.  | 
Click Start, and then click Control Panel. | 
 
| b.  | 
Double-click Add or Remove Programs, locate and then click Windows XP - Software, then click Windows Genuine Advantage Notifications, and then click Click here for support information. | 
 
| c.  | 
In the Support Info dialog box, verify the version number, and then click Close. | 
 
 
 | 
| 3. | 
Rename the following files by changing the extension to .old: 
| » | 
Rename %Windir%\system32\WgaLogon.dll to %Windir%\system32\WgaLogon.old | 
 
| » | 
Rename %Windir%\system32\WgaTray.exe to %Windir%\system32\WgaTray.old | 
 
 
 | 
| 4. | 
Restart the computer. | 
| 5. | 
Unregister LegitCheckControl.dll by using 
Regsvr32. To do this, follow these steps: 
| a.  | 
Click Start, click Run, type cmd, and then click OK. | 
 
| b.  | 
At the command prompt, type the following, and then press ENTER:
 Regsvr32 %Windir%\system32\LegitCheckControl.dll /u 
 | 
 
 
 | 
| 6. | 
Restart the computer. | 
| 7. | 
Click Start, click Run, type cmd, and then click OK. | 
| 8. | 
At the command prompt, delete the following files by typing the Del command. Press ENTER after you type each command. 
| » | 
Del %Windir%\system32\wgalogon.old | 
 
| » | 
Del %Windir%\system32\WgaTray.old | 
 
| » | 
Del %Windir%\system32\LegitCheckControl.dll | 
 
 
 | 
| 9. | 
At the command prompt, type regedit.  | 
| 10. | 
Locate and then right-click  the following registry subkeys. Click Delete after you locate each subkey. 
| » | 
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\ 
CurrentVersion\Winlogon\Notify\WgaLogon | 
 
| » | 
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows \CurrentVersion\Uninstall\WgaNotify | 
 
 
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Source: Microsoft KB
                            
                         
Ricky McDermon