> Why i can play "Double Dragon - Bootleg" but canīt play some roms of minor size
> (snow brothers,prehisle, etc.)?
>

Why don't you tell us! Do you get any errors or anything? What are you using to play? I'm assuming MAME, right? (See what I mean about telling us what exactly is happening?) If you're using MAME, make sure you have the bootleg ROM sets (son;t ask here please).

Jason