Phoenix Technologies of Milpitas, CA, said today that it will acquire TouchStone Software, the North Andover, MA-based maker of tools for diagnosing and updating Windows personal computers. Touchstone stockholders will get $1.48 for each share, making the total value of the deal roughly $18 million. TouchStone’s core product is a yearly service that gives customers access to the company’s database of software drivers for PC peripherals. Phoenix develops PC firmware such as the “BIOS” that loads the operating systems software into your computer when you start it.