Remove WGA Notifications

Official Method by Microsoft - more information here.

First Method

1. Lauch Windows Task Manager.
2. End wgatray.exe process in Task Manager.
3. Restart Windows XP in Safe Mode.
4. Delete WgaTray.exe from c:\Windows\System32.
5. Delete WgaTray.exe from
c:\Windows\System32\dllcache.
6. Lauch RegEdit.
7. Browse to the following location:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft Windows NT\CurrentVersion\Winlogon\Notify
8. Delete the folder ‘WgaLogon’ and all its
contents
9. Reboot Windows XP.

Note: With this method, you may be prompted to install
WGA Notifications again which can still be unselected.

Second Method

Another alternative suggested by dman is by using
System Restore to restore the PC to a previous restore
point that WGA Notifications hasn’t kicked in, and
then carefully stop KB905474 from been applied to the
system. To use System Restore, go to Start -> All
Programs -> Accessories -> System Tools -> System
Restore.

Note: Again, you may be prompted again to install WGA
Notification, so it must be bypassed.

Third Method updated

This method involves using a cracked version of
LegitCheckControl.dll to replace the original copy of
LegitCheckControl.dll, and thus bypass the WGA
validation and make Microsoft believes that your copy
of Windows is genuine. To get rid of WGA Notifications
warning messages, the patched version of WgaLogon.dll
and WgaTray.exe to replace the existing files.

To apply the patch by replacing the files manually,
try to end the respective processes in the Task
Manager before deleting the existing files. Most
likely is you will have to restart your PC in Safe
Mode in order to replacing the original copy of
LegitCheckControl.dll and related files. However,
there has been automatic updater and even cracked WGA
installer that automatically apply the patched version
of WGA files.