Firmware is the software that is embedded on the read-only memory or ROM; programmable read-only memory, or PROM; or erasable programmable read-only memory, or EPROM, of a hardware device, such as a cellphone or a computer. Most devices have firmware updates from time to time, but if you run an update and something goes wrong you can't just uninstall it. The ROM, PROM and EPROM need the firmware to function. Instead of just removing it you have to replace it with another version of firmware.
Search the Internet for another version of the firmware for your device. The firmware can be an older version, a newer version or an alternate version created by a third party, like the third-party firmware made for iPhones.
Download the firmware onto your computer or onto your device, if possible.
Connect the device to your computer, if needed, and run the new firmware. Double-click on the firmware to run it. Select the location where you want to install the firmware and click "OK." Once the new firmware finishes installing, the old firmware will no longer be on your system.