Dell and Sony are both expected to launch their first Media Center PCs this fall, sources familiar with the companies' plans told CNET

The two companies did not offer computers using the initial version of the Windows XP Media Center operating system, but are expected to enter the market once Microsoft introduces a new version of the operating system later this month. Microsoft has scheduled events across the United States on Sept. 30 to unveil the next version of Media Center, code-named Harmony.