CWmike writes "Microsoft will block users running counterfeit copies of Windows from installing the free Security Essentials antivirus software, said Alex Kochis, director of Microsoft's Genuine Windows team, in a post to a company blog. On-again, off-again debates about the wisdom of blocking security-oriented downloads like patches or defensive software have centered around the argument that Microsoft should protect all users, including pirates, since hijacked PCs threaten the entire Windows ecosystem. In this case, though, one analyst isn't buying that line. 'I can't see any justification for making Microsoft give away Security Essentials [to counterfeit Windows users],' said John Pescatore, Gartner's primary security analyst. 'Those people have many other choices, including free. There are plenty of alternatives to Security Essentials,' he said, adding that that makes a difference. Windows patches, on the other hand, aren't available from anyone but Microsoft."