Help with adding east europe maps on NAVNGO - IGO8 VER8.3.2

Hello,
I am new in GPS world.
I get GPS system from my brother. APEX GPS-4313 , OS : Windows CE 5.0
I get the GPS system with NAV N GO - IGO8, version: 8.3.2.92379 (LINCES) with my country maps (Israel) .
I tried to add Eastern Europe maps (I searched the net & found fbl files), I added this files to the match folders, but can't see the new maps. seems that my GPS can't read the new maps.

I think that my IGO OR my gps system is locked.
How can hack/install/unlock the GPS/IGO8?

Please help me with this issue, please send links for downloads OR information.

best regards,
Sam