Microsoft sues 20 dealers for software piracy

The lawsuits, filed against 20 companies in nine US states are part of a big Microsoft initiative to fight counterfeiting and piracy.

Senior Microsoft pleader Mary Jo Schrade said: "We will not sit by as consumers are put at risk and honest resellers are hurt."

Microsoft said that it collected 384 Windows XP disks and when analysed found 43 per cent of them contained code not part of the genuine article.

That, said Microsoft, could result in denial of service attacks, bypass password protection and corrupt memory. µ