I just did this for a laugh and didn't expect it to work. I went to microsoft.com using IE4Linux ( http://www.tatanka.com.br/ies4linux/page/Main_Page ) and tried to download Windows Defender, on Xubuntu. Of course, I was asked to do the Genuine Advantage test. I used the alternate authentication method (IE4Linux doesn't support Active X), downloaded and then ran the genuine advantage application (which took quite a while to start). It gave me a code that I pasted into the authentication box, and to my surprise it verified me and forwarded me to the download page. This just goes to show how rubbish they're validation software is. I thought it was funny though, so I've uploaded a recording of it to rapid share, which you can get here: http://rapidshare.com/files/37580147/recording.ogg
(the file is about 10MB, so it might take a while to get)