Hey there, Ahmed.
As far as I know, there shouldn't be any firmware update necessary for flash drives. I don't know what was the firmware you've installed, but this might have bricked the device. In other words it might be irreversible. Give it a try with a different computer/device to see if the same thing happens again. If you still have no luck recognizing the flash drive, perhaps the best course of action would be to get in touch with the pen drive manufacturer's customer support and ask for help. Perhaps they might be able to provide specific firmware which could fix things up.
Hope that helps. Please let me know how it goes.
Boogieman_WD