I don't know what languages use now, I will give you an example of files for the United Kingdom:

Read here: http://www.topsony.com/forum/far-manager-f31/flash-k800-cid53-k810-software-cid53-begginers-t11605-mensaje89845.html#post89845, but use these files:

1. W580_R8BE001_MAIN_GENERIC_LA_RED53 (Downloads -> Firmware -> W580 -> R8BE001_RED53)
2. W580_R8BE001_FS_EUROPE_3_RED53 (Downloads -> Firmware -> W580 -> R8BE001_RED53)
3. HB1-06_Gen_CDA102568_12_R8A_GENERIC_EUROPE_3 (Downloads -> Custom Files -> w580custpack)

EUROPE_3 contains the following languages: English - Danish - Dutch - French - German