i got drivekey modchip and i download games from usa and pal i live in uk so most pal games work but no games from usa work

i have been told that my wii shud play all games that i download is this true?

also i tried to softmod wii before i modchiped it and i know you can do both but when i try to softmod again it wont any1 know why

thanks in advance if you can answer my questions