It’s extremely easy to remove windows genuine advantage notification in xp
Go to My Computer
Choose C drive
Go to Windows
Open system32 folder
Open folder KB905474 (If you can’t see this folder, go to Tools –> Folder Options –> View —> Show hidden files and folders— click OK
Remember to remove everything in folder KB905474 and after that restart your computer. This should totally remove the windows genuine advantage notification pop up message in Windows XP.