An information processing system comprising a host device and a storage device, the storage device being connected with the host device, the storage device including a nonvolatile memory in which data reading and writing is performed by a page unit and data erasing is performed by a block unit twice or larger natural number times as large as the page unit, and a controller that controls the nonvolatile memory, the host device comprising: an interface driver for operating the storage device, the interface driver enabling a first interface driver for supporting read and write operations of the nonvolatile memory and a second interface driver for supporting only the read operation of the read and write operations of the nonvolatile memory to be alternately selected; and a control unit configured to: require the storage device to send statistical information to the host device; compare the statistical information received from the storage device with a first threshold value; determine whether or not the storage device is to be recognized as read only memory in which only the read operation of the read and write operations is possible when the statistical information exceeds the first threshold value; switch the interface driver from the first interface driver to the second interface driver when determined to recognize as the read only memory, compare the statistical information received from the storage device with a second threshold value different value from the first threshold value, when the host device recognizes the storage device as a read only memory; and switch the interface driver from the second interface driver to the first interface driver when the statistical information does not exceed the second threshold value; wherein, when the host device determines that the storage device to be recognized as read only memory is connected to the host device, the host device is further configured to select the second interface driver, whereby the host device recognizes the storage device as a read only memory without issuing a write request to the storage device. an interface driver for operating the storage device, the interface driver enabling a first interface driver for supporting read and write operations of the nonvolatile memory and a second interface driver for supporting only the read operation of the read and write operations of the nonvolatile memory to be alternately selected; and a control unit configured to: require the storage device to send statistical information to the host device; compare the statistical information received from the storage device with a first threshold value; determine whether or not the storage device is to be recognized as read only memory in which only the read operation of the read and write operations is possible when the statistical information exceeds the first threshold value; switch the interface driver from the first interface driver to the second interface driver when determined to recognize as the read only memory, compare the statistical information received from the storage device with a second threshold value different value from the first threshold value, when the host device recognizes the storage device as a read only memory; and switch the interface driver from the second interface driver to the first interface driver when the statistical information does not exceed the second threshold value; wherein, when the host device determines that the storage device to be recognized as read only memory is connected to the host device, the host device is further configured to select the second interface driver, whereby the host device recognizes the storage device as a read only memory without issuing a write request to the storage device. require the storage device to send statistical information to the host device; compare the statistical information received from the storage device with a first threshold value; determine whether or not the storage device is to be recognized as read only memory in which only the read operation of the read and write operations is possible when the statistical information exceeds the first threshold value; switch the interface driver from the first interface driver to the second interface driver when determined to recognize as the read only memory, compare the statistical information received from the storage device with a second threshold value different value from the first threshold value, when the host device recognizes the storage device as a read only memory; and switch the interface driver from the second interface driver to the first interface driver when the statistical information does not exceed the second threshold value; wherein, when the host device determines that the storage device to be recognized as read only memory is connected to the host device, the host device is further configured to select the second interface driver, whereby the host device recognizes the storage device as a read only memory without issuing a write request to the storage device.