This post provides Huawei MP of E303Fh with Win.8.1 Support UTPS23.015.02.01.910 MAC23.015.02.01.910, which can be downloaded from the link which is provided at the end of the post. Once downloaded, extract in a folder using unzip software, and process as mentioned in the respective post. Wrong firmware/software change of a Huawei / ZTE modem/router may dead your device permanently. While running the Huawei firmware update, it will prompt for firmware/flash code as a password. You can generate the firmware code from the universal master code tool.
Disclaimer: Administration of routerunlock shall not be liable if an unknowing change of your modem/router / MiFi firmware. Moreover, if you want any specific firmware related to Huawei dongle / Pocket MiFi, leave a comment; it will be published if it is available. All the firmware publicly posted at routerunlock is free of cost, and there is no need to pay anyone.