A Silicon Valley company is claiming a major victory in its efforts to sell computers to schools that might otherwise be enticed by low-cost laptops such as the green-and-white XO from One Laptop Per Child or Intel’s Classmate PC. NComputing said Monday it would be providing computers in 5,000 schools in the Indian state of Andhra Pradesh. Because of the particulars of NComputing’s system, the company says 1.8 million students will have access to the machines to learn computing skills and productivity software.