This file contains multiple .inf files. After extracting the .inf files, open them to see which modems are supported for that particular file. You have to sort through some stuff that does not make much sense, but eventually you will see the modem types. After determining what kind of modem you have, to install the .inf file just click on modems and do not let windows search for the device. Say you will pick from list and check the "have disk" button. Browse to get to the file location and say OK.