in 1975, Gates dropped out of Harvard to start a software company with Paul Allen called Microsoft. The company was doing well, but it was in 1980 that Gates made a deal with IBM that would change computing. Microsoft reached a deal to provide the MS-DOS operating system on the new IBM PC. Gates sold the software to IBM for a fee of $50,000, however he held onto the copyright of the software. When the PC market took off, Microsoft also sold MS-DOS to other PC manufacturers. Soon, Microsoft was the operating system in a large percentage of computers around the world.