BBC News Online: Business

Microsoft's net malaise

The network of internet sites owned by Microsoft have been inaccessible to users for most of Wednesday.

The sites affected include the popular internet portal msn.com and the e-mail system hotmail.com, which has over 74 million users worldwide.

Worryingly, Microsoft was unsure of the cause of the problem, even eighteen hours after the sites were reported out of order.

Hacker fears

"We have been trying to determine the cause of the problem since we became aware of it," said company spokesman Adam Sohn.

"When we are sure of what is happening, we'll be able to fix it," he added.

Microsoft has not ruled out the possibility that a hacker is causing the trouble.

The Microsoft main corporate site has already suffered an embarassing problem when a hacker stole part of the code for products in development in October.

Microsoft's car purchasing service, the house buying site and the Expedia travel service were all also inaccessible to the public on Wednesday.

Other sites which have also crashed this month include the auction site eBay and the biggest online retailer Amazon.com.