A customer, left, looks at computers in a store in Beijing, China, Thursday, June 25, 2009. Washington is calling on Beijing to revoke an order to personal computer makers to supply Internet-filtering software with every PC, adding to an array of disputes between the major trading partners. Beijing told manufacturers in May to install "Green Dam Youth Escort" Web-filtering software or supply it on a disk with every PC made beginning July 1 for sale in China. PC makers say they are studying the order.