I tried to download Windows Defender from the Microsoft website.  I could not download it because the validation of my Windows XP failed, even though it is genuine Microsoft.  It gave me a 0x80080293 error.  I went to the MS bulleting board, where there is lots of discussion about this problem, but none of it is helpful.  Does anyone know of a solution?

   My validation of WinVista also failed, but there was a manual validation option (I don't remember what it was called) where they give you a number and you enter it in the box.  That worked.