Download this rom: https://www.mediafire.com/download/zs3k14xa803olpo/APP-SW_X1_GENERIC_UK_1213-6450_R3AA010__KOVS.nbh

put it on a <2gb microsd card formatted as fat32

rename the file to kovsimg.nbh

put the microsd into the phone

power the phone on with vol down + power , to enter the flashing mode

follow on-screen instructions to flash. the flash process takes maybe 5 minutes or longer.

once done it will say "Update Success", then you can turn the phone off (in my case by removing the battery and inserting it again), remove the microsd, then turn the phone back on normally. it will take long to boot but you will get to the winmo setup in english