The Magnuson-Moss Warranty Act, passed in 1975, protects you from having to select a particular brand of memory in order to be covered by a manufacturer's warranty. More information may be found at www.ftc.gov
In addition to the Magnuson-Moss Warranty Act, most major computer manufacturers maintain 100% of the warranty of their computer systems regardless of whether you use third party memory, such as SimpleTech memory. These companies include HP, IBM, etc.. For a complete listing click here.