Many new computers have new style modems, which are software controlled .
In some cases, if there is a memory glitch or too much demand on the processor, the modem may lose the connection. There is also some question about PCI modems having similar problems. These modems use the newer PCI slot in your computer's motherboard, however they tend to need a driver to make them work. Also, the new USB modems that plug into the USB port use a driver . Once again software.