Is my hardware good enough?

[Insignificant]

Hi there,
im totally new to dolphin. I want to play with it some Games (Mario Galaxy 2, Mario Kart). I usually don't play that much games,
so i never bought game console, in the last years. Besides i don't even own a tv, just my pc.

So it would be really great if i could play these games here, but my question is, is it legal?

I know that the problem with a PS2 emulator is, that the emulator itself might be legal, but it does need a BIOS rom to work, which
makes it more or less illegal. So im little worried about that.

Also i wanted to know if my computer could take it?

Windows 7 x64
Intel Core i7 870
12 GB Ram
Radeon HD 5750

[DefenderX]

1st - Yes, Dolphin is legal as long as you dump your original games
2nd - Your CPU is pretty good, most games will run well. Super Mario Galaxy and some others (e.g. The Last Story) will be playable, but not at fullspeed. Some very demanding games need an Core i5-3570k @ 4.2Ghz.