A South Korean court handed Microsoft a setback Tuesday in the software giant's appeal of an order to change its business practices and pay a $34 million fine.

The court rejected Microsoft's request to set aside an order from the country's Fair Trade Commission.  Regulators had ordered Microsoft to make it easier for customers to use software from rival companies to play music and movies as well as handling instant messaging.

Microsoft's ubiquitous operating system gives instructions to most of the world's desktop computers. 

Critics accused the company of abusing its dominant market position to unfairly shut out rivals from the developing market for media and message software.

Microsoft has another appeal pending in this case.